-^i ^ ^^ W^^'d^' '^^.£j 'j^m^ 2^ vw f. LIBRARY OF CONGRESS. ef ^- -' Shelf ...Mb4 UNITED STATES OF AMERICA. "WW m^xym^^^^. ^^^ffi l^^^^^i^Ps^VJ^^S^-^^^^^^f^ "r ^^^8 ^^/^^^^a ^%"~^^^p ^K ^^^^^^^^^^w^^^^^^S ^^^^^5 ^M^^^^^B »^ STOCK-BREEDING: A PKACTICAL TEEATISE ON THE APPLICATIONS OP THE LAWS OF DEVELOPMENT AND HEREDITY TO THE IMPROVEMENT AND BREEDING OF DOMESTIC ANIMALS. MANLY MILES, M. D., PaOFESSOB OP AGBICULTTTEK IN MASSACHCSKTTS AGEIOXJLTTTBAL COLLSGB. /■A / NEW YORK: D. APPLETON AND COMPANY, 1, 3, AND 5 BOND STKEET, 1883. u 1 COPTEIGHT BT D. APPLETOJSr AND COMPANY, 1878. COPTEIGHT BY D. APPLETON AND COMPANY, PEEFAOE. It is somewhat remarkable, in this book-making age, that there is no systematic work accessible to the student in which the known facts and principles of the art of improving and breeding domestic animals are presented, in convenient form, for stndj and ref- erence, notwithstanding the importance of live-stock to the farmer, and the wonderful progress that has been made in its improvement since the time of Bake- well. The present attempt to supply this want has been made in response to the repeated sohcitations of per- sons interested in stock-breeding, who have attended my lectures on this subject, in various places, for sev- eral years past. In a popular exposition of the principles of an art that is almost exclusively based upon the experience of practical men there is little opportunity for origi- nality, aside from the classification and arrangement of facts, and the inferences, in some instances, that iv PREFACE. may be drawn from them in explaining the practice of the most successful breeders. It is believed that a systematic statement of what is already known in the practice of the art is of greater importance, at the present time, than any new tiniths, as it must furnish the only consistent foundation for future progress and improvement. The numerous cases that have been collected to illustrate the various topics under discussion have been compiled, as far as possible, from original sources and presented in their original form — ^references, in nearly all cases, being given to the works from which they are quoted. This feature of the work will be of interest to the student who wishes to study the subject in greater detail, as it will, to some extent, serve as an index to authorities that may be profitably consulted. In the limits of a popular work it is of course im- possible to treat each topic exhaustively, and the at- tempt has been made to present only such an outline of the principles of the art as would be required in a text-book for students, or a work of reference for farmers. The acknowledgments of the author are due to the well-known animal-artist John R. Page, of Ben- nett, New York, for the spirited illustrations in the chapter on " Form," all of which are from life, with PREFACE. V the exception of Fig. 8, wHcli is after a sketch by the Hon. Francis Kotch. It is to be hoped that the resume of cases here presented may lead breeders to recognize the impor- tance of placing on record the additional facts, from their own experience, that are required for a more complete discussion of the subjects treated in this volume. Lansing, Michigan, July 20, 1878. OONTEE"TS. CHAP. I. Breeding as an Art .... PAOB 1 n. Heredity op Normal Charactj!;ks . 11 in. Heredity op Diseases .... . 22 IV. Heredity op Acquired and Abnormal Characters 40 V. Atavism ...... . 66 YI. Law of Correlation .... 83 VII. Variation ..... . 92 Vin. Fecundity ...... 108 IX. In-and-in Breedinq .... . 137 X. Cross-Breeding ..... 190 XL Relative Influence op Parents . 215 XTT Influence of a Previous Impregnation 255 Xlll. Intra-Uterine Influences . 281 XIV. Sex 296 XV. Pedigree ...... . 337 XVL Form of Animals as an Index of Qualities 352 XVIL Selection ..... . 385 XVIII. Period of Gestation . . 400 PRINCIPLES OF STOCK-BREEDING, CHAPTEH I. BEEEDma AS AK AET. The art of breeding domesticated animals, for the various purposes to which they are adapted, has been practised from the earliest times. The oldest writers on agriculture ga\^e directions for the breeding and improvement of cattle, and some of their maxims are often repeated by modem authori- ties as the best practical guides to the farmer. It has long been known that the characteristics of parents were transmitted to their offspring, and the results of observation were tersely expressed in the familiar aphorism, " like produces like." As a natural corollary of this generally-accepted law of the animal organization, the rule " breed from the best " very early found a place among the approved maxims of the art. The principles of breeding, up to the time of Bake- well, were essentially comprised in these two apo- thegms ; but it is evident, from the practice of breed- ers,'that they did not fully appreciate the extended ap- 2 PRINCIPLES OF STOCK-BREEDING. plications of these empirical expressions, that repre- sent the fundamental principles of the best modern practice. The early breeders, like many at the present time, had no consistent system of selection. The ".best" of any given selection for breeding, made in accord- ance with the time-honored rule, differed in all essen- tial details of form and quality from the " best " that were selected at another time. Their standard of excellence was, in fact, constantly changing, so that no real progress in the development of the most valuable qualities could be made. Shortly after the middle of the last century, Robert Bakewell, of Dishley Grange, Leicestershire, England, originated a new system which he successfully prac- tised in the improvement of Leicester sheep. Long-horn cattle, and Black cart-horses. His belief that the fa- miliar maxim, " like begets like," was not limited to a general similarity of the offspring to the parent, but extended to the minutest details of the organization, led him to adopt for his guidance a definite standard of excellence representing the form and internal quali- ties that were best adapted to the highest develop- ment of the animal for a special purpose. His critical study of the form and proportions of animals, and their relations to the most desirable quali- ties, enabled him to develop an ideal model of perfec- tion, that he kept constantly in view when making his selections for breeding. In his sheep and cattle he endeavored to secure a large proportion of choice parts in the carcass, a supe- rior quality of flesh, with ,a tendency to early maturity. BREEDING AS AN ART. 3 and uniformitj in the transmission of their most valu- able qualities to their offspring. Beautj in the form and proportions of his animals was always made to contribute to the development of useful characters. Mr. Bake well's success in the im- provement of the animals he was breeding must be attributed to the exercise of a combination of talents that would have made him eminent in any profession or pursuit. A correct and well-trained eye enabled him to detect the slightest variations of form; and these, from his knowledge o£ the animal organization, ob- tained by long-continued and systematic observation, he associated with the correlated qualities they rep- resented. Kelying upon his own good judgment, which was not biased by non-essential conditions or fanciful the- ories, he not only accepted all that was consistent in the received rules of the art, but established new prin- ciples of the greatest practical importance. He seems to have been apt in tracing the relations of cause and effect, and methodical and persevering in the execution of his well-considered plans for im- provement. "With the spirit of a true artist, he endeavored to mould the plastic forms of his animals to give expres- sion to his ideal conception of the qualities that con- stitute perfection. The method of Bakewell has been successfully practised by other able men ; and we now have, as the result of their labors, a variety of improved breeds of remarkable excellence, each differing from the others 4 PRINCIPLES OF STOCK-BREEDING. in the particular characters that adapt them to special conditions and purposes. Success in the breeding of live-stock, as in all other departments of farm management, must be measured by the actual value of the products, and the profits that may be derived from them. The relative value of animals depends upon their adaptation to a particular purpose, and the returns they make for feed consumed. It is evident that, where a particular form of animal product is the lead- ing object, the greater value will be placed upon the animal that excels in its production. Excellence in other directions may be desirable, but it will not compensate for a deficiency in the special qualities required. The return obtained, in any form of animal prod- uct, for feed consumed, is of the first importance in estimating the value of animals. Mr. Bakewell re- garded live-stock as machines for converting the vege- table products of the farm into animal products of greater value ; and Sir John Sinclair expresses the same idea when he says, " Under the head of live- stock are comprehended the various sorts of domesti- cated animals which are employed by man as instru- ments for converting to his use, either by labor or otherwise, those productions of the soil which are not immediately applicable to supply his wants in their natural state." ^ The animal that furnishes the largest amount and the best quality of the desired animal product, from a given amount of food, would xmdoubtedly be the * " Code of Agriculture," p. 84. BREEDING AS AN ART. 5 " best ; " or, looking more particularly at tlie activity of tlie animal machinery, it might be said that the animal that converts the largest amount of food into animal products of the best quality, with the least possible waste of material, would be the most valu- able. It is often assumed that animals that eat but little are the most profitable, but this error is evidently founded on mistaken notions of the functions of ani- mal life, and the true place that they occupy in the economy of the farm. A machine that will convert the largest amount of raw material into the desired product, with the least possible wear, and the least expenditure of fuel to furnish the required motive- power, would be more valuable than one that required less fuel, but in which the capacity for efficient work was diminished in a greater ratio. The repairs of the animal machine are made at the expense of food consumed, and, if the animal is capa- ble of digesting and assimilating only what is required for this purpose, it would be comparatively worthless, as a profit can only be obtained from the food assimi- lated in excess of this amount. In my experiments in feeding swine, the best re- turns for feed consumed were obtained when the ani- mals ate the most in proportion to their live weight, and this is undoubtedly the rule in stock-feeding. This is readily explained by the fact that, when a large amount of food is consumed by an animal, pro- viding it is capable of digesting and assimilating it, the j^ojportion of food required to supply the waste of the tissues and keep the animal machinery in work- 6 PRINCIPLES OF STOCK-BREEDING. ing order is less than when a smaller amount is con- sumed/ It wiU not, then, be desirable to breed animals that eat but little, as we cannot reasonably expect them to give as large a proportionate return for feed consumed as those that have efficient digestive organs of greater capacity. A comparison of the results obtained with different animals is generally neglected by farmers, and they therefore make too little difference in the price of their best animals, that are capable of returning a fair profit on the food consumed, and those of inferior quality, that do not, perhaps, pay for their keep. The great difference in the relative value of ani- mals will be best shown by a few illustrations. One cow yields five pounds of butter a week, which, at twenty cents a pound, would be one dollar, or twenty dollars for twenty weeks, which we will assume is the period of usefulness for the year. Another yields eight pounds of butter a week, worth one dollar and sixty cents, and the total return for twenty weeks would be thirty-two dollars, or twelve doUars more than was realized from the first cow. This difference represents the interest on one hundred and twenty dollars, at ten per cent, for the year. On the same basis, a cow yielding ten pounds of butter a week would earn forty dollars in twenty weeks, or twenty dollars more than the first cow, and this difference would be the interest on two hundred dollars for the year. Three pounds of wool from one sheep, at fifty ^ " Michigan Agricultural Report," ISlB, p. 120. BREEDING AS AN ART. 7 cents per pound, would bring one dollar and fifty- cents ; and six pounds from another, at the same price, would bring three dollars, a diiference of one dollar and fifty cents, or the interest on fifteen dollars. Even if it is claimed that the animals giving the greatest return consume considerably more food than the inferior ones, there would still remain a great dif- ference in the profits of their products. If in the same way we estimate the relative value of sires, by comparing the qualities of their offspring, it would be seen that one capable of increasing the value of the flock or herd would be well worth a good price ; while another, that could not be relied on to impress any good qualities upon his offspring, would be dear at any price. The object of the art of breeding is the improve- ment of animals in those qualities that have a definite value, among which are the production of meat, and milk, and wool, and labor. Breeders who have been the most successful in improving the various pure breeds have endeavored to obtain the highest development of some one of these qualities ; while the others, which they looked upon as of secondary importance, have been quite generally neglected. It must not, however, be assumed that these quali- ties are absolutely incompatible, so that a high degree of excellence in two or more of them cannot be ob- tained in the same animal ; but it is undoubtedly easier to secure an extraordinary development of a single character than to obtain the same degree of excellence in two or more at the same time. 8 PRINCIPLES OF STOCK-BREEDING. Wheii tlie entire energies of tlie system are acting in a particular direction, as they must do to insure the highest development of a single quality, there is no residuum of force for the development of other quali- ties that are not strictly correlated with the one that is made dominant. The modern art of breeding is founded on the practice of the most successful breeders, and its rules have been almost exclusively empirical in their origin. The science of physiology, by explaining the prin- ciples on which many of these rules are based, has de- fined the limits of their applications with greater ex- actness, and suggested new fields for investigation. In its progress the art has, however, kept constant- ly in advance of the allied science of physiology, which it has aided in developing by presenting, in its definite facts, the required data for successful scientific study. ^ With the progress of knowledge, the unexplained precepts of the art are gradually diminishing, and the many theories that have been framed from partial views of the truth must be replaced by consistent principles of general application. The inferior quahty of the live-stock on the farms throughout the country shows that the relations of the art of breeding to the practice of agriculture have been too generally overlooked by farmers. Looking upon live-stock as a special interest, and ^ WheweU remarks that "in all cases the arts are prior to the related sciences. Art is the parent, not the progeny, of science : the realization of principles in practice forms part of the prelude, as well as the sequel, of theoretical discovery " (" History of the Inductive Sciences," vol. i., p. 240). BREEDING AS AN ART. 9 referring to their past experience witli animals that were entirely unfitted for any useful purpose, it is not strange that the assumption that " live-stock will not pay " is so often repeated. The same opinion seemed to prevail among the farmers of Rome in the first century, and Columella pointed out to them the fallacy of this prejudice against one of the most important interests of the farm.^ Conrad Heresbach, quoting Fundanius in Yarro, compares the tillage of the soil and the interest in live-stock to two instruments in an orchestra, each differing in sound ; and he terms " the grazier's trade the treble, and the tiller's occupation the base," each aiding in the harmony as a whole.' Fitzherbert expresses the same idea when he says, " An husbande cannot well thryve by his corne with- out he have other cattell, nor by his cattell without come, for els he shall be a byer, a borrower, or a beggar." ' George Culley, in his valuable treatise on live- stock, says, "According to the present improved sys- tem of farming there is such a connection between the cultivation of the ground and breeding, rearing, and fattening cattle, sheep, and other domestic ani- mals, that a man will make but an indifferent figure in rural affairs if he does not understand the latter as well as the former." * * " Columella of Husbandry," book vi., p. 256. 2 "Foure Bookcs of Husbandrie" (1586), p. 111. 3 " Boke of Husbandry " (1532), p. 34 (reprint, 176V). 4 " Live-stock," by Culley, fourth edition, 1807, p. 1. 10 PRINCIPLES OF STOCK-BREEDING. The statements of these writers were not made on theoretical gronnds, but represented the opinions of those who were most successful in their system of practice. At the present time farmers throughout the coun- try should give greater attention to live-stock, as the first step in the improvement of their system of farm- ing. Animals of the best quality, that are adapted to the conditions of the farm and the particular purpose that the system of management demands, will yield profitable returns for the feed consumed, and furnish the best means of enriching the soil for the growing of grain. The principles that guide the breeder of pure-bred stock are likewise applicable to the improvement of the common stock of the farm. It is not to be expected that all persons will be equally successful in producing animals of extraordi- nary merit, but it is, nevertheless, true that a careful study of the principles of the art, which are easily understood, will enable the farmer to make improve- ments in his stock that will add largely to his profits. CHAPTEE 11. HEREDITY OF NORMAL CHAEACTEES. The iiiheritance by the offspring of the characters of the parents, at the time of procreation, has been generally accepted as a law of the animal organiza- tion. Although there are many apparent exceptions to this law, an examination of all the facts relating to the hereditary transmission of structure and qualities will, however, show that it is not only constant in its action, but extends to every feature of the organiza- tion, and that the supposed exceptions are the result of the predominant influence of other laws that ob- scure the hereditaiy tendency, for the time being, without wholly suppressing it. The resemblance of offspring to parents, so fre- quently remarked, is not, as might at first be sup- posed, confined to the external and more obvious characters, but manifests itself in the internal struct- ure and functional activity of the system. In fact, at the moment of birth, the sum of the characters and qualities of the young animal have been derived from its parents, and we shall find reason for the belief that they include every peculiarity in the organization of both parents. 12 PRINCIPLES OF STOCK-BREEDING. Tlie nervous system and mental condition, the organs of nutrition and reproduction, the habits, pre- dispositions, and temperament, the bones, the muscles, and the powers of endurance, that characterize the parents, are all reproduced in the offspring without essential change in their characteristics. Illustrations, drawn from the different departments of organic life, will serve to show the extent and per- sistent action of the law of heredity, and aid us in de- termining its applications in the breeding of domestic animals. In the geological formations, representing immense periods of time, fossil species and generic f onns pre- sent the same essential characters throughout their entire range. The various species of wild animals are readily recognized wherever found, and the lapse of time represented in the historic period has made no appre- ciable change in their characters. The animals that have been preserved in the monuments of Egypt for thousands of years are essentially the same as those now found on the borders of the Nile.^ So far as the art of breeding is concerned, a con- sideration of the various theories of evolution can be of no practical value, and the observed repetition of generic and specific forms may be assumed to repre- sent a constancy in the inherited characteristics of animals. The cycle of changes through which the embryo passes in the process of development remains the * Colin, "Physiologie Compar^e," tome ii., p. 533 ; Darwin's " Ani- mals and Plants under Domestication," vol. i., pp. 30-60. HEREDITY OE NORMAL CHARACTERS. 13 same in tlie various species, while the disappearance of organs that serve a temporary purpose takes place at the same period of growth. The races of men, when pure, are readily distinguished by peculiarities in complexion, features, and general organization. The Jews and the gypsies have been cited as illus- trations of the hereditary transmission of the peculi- arities of a race, as they do not intermarry with other families, and their distinguishing characteristics have remained the same for centuries.* The uniformity observed in the various breeds of domestic animals is the result of the inheritance of the characters that adapt them to the conditions under which they have originated. In the improved breeds advantage is taken of the hereditary transmission of certain family peculiarities that have been ingrafted upon those of the original breed. As the origin and development of these improved characters have no relation to our present subject, they will be considered in another chapter. In almost every breed there are favorite families, that are prized by breeders for the persistence with which they stamp their peculiar characters upon theii offspring. The breeders of sheep will call to mind the influ- ence of the Ellman and the Webb sorts in the im- provement of the Southdowns, and of the Dishley family in the development of the Leicesters. The different cabanas of merino sheep in Spain, ^ " Heredity," by Ribot, pp. 112-114 ; " Journal of the Royal Agri- cultural Society," vol. xiv., p. 106 ; Goodale's " Principles of Breeding," p. 23 ; Anderson's " Recreations in Agriculture," vol. i., p. Tl. 14 PRINCIPLES OF STOCK-BREEDINa that were kept distinct for many years, were charac- terized by peculiarities that were uniformly inherited.^ Of the offshoots of the original Spanish-merino sheep, the Silesian family bred in Europe, and the Rich and the Hammond families in the United States, furnish further illustrations of the hereditary trans- mission of family characters. Of cattle, the Booth and the Bates families of Short-horns, the Quartley family of Devons, the Dish- ley family of Long-horns, and the Ben Tompkins sort of the Herefords, may be mentioned as among the favorites of breeders, on account of the marked he- redity of their peculiar qualities. Muscular strength, in connection with remarkable powers of endurance, is frequently observed in par- ticular families. " In ancient times there were fami- lies of athletes, and there have been families of prize- fighters. The recent researches of Galton as to wrest- lers and oarsmen show that the victors generally belong to a small number of families, among whom strength and skill are hereditary." ' The large proportion of successful racers tracing their ancestry to Herod and Eclipse, not in a single line only, but in several, furnish a good illustration of the hereditary transmission of muscular power. It is said that " Eclipse begot 334 and Herod 497 winners." ^ ^ Livingstone on " The Sheep," p. 21 ; Morrell's " American Shep- herd," pp. 'Zl-'ZS ; Randall's "Practical Shepherd," p. 14 ; Youatt on "Sheep," p. 156. 2 " Heredity," by Ribot, p. 6. 2 " The Horse," by Stonehenge, American edition, p. 142 ; Stone- henge, " British Rural Sports," p. 282 ; " The Horse of America," by Frank Forrester, vol. ii., p. 265 ; Darwin's "Animals and Plants under Domestication," vol. ii., p. 21. HEREDITY OF NORMAL CHARACTERS. 15 The most successful American trotting-horses are said to belong to but three families, and of these the Messenger is thought to be the best, as it has fur- nished a larger number of fast trotters than any other.* There are families that inherit that peculiar or- ganic structure of ear, nervous system, and vocal or- gans, that gives rise to what is recognized as musical talent. One of the most remarkable instances of this form of heredity on record is that of the family of Sebastian Bach. " It began in 1550, and continued through eight generations. . . . During a period of nearly two hundred years this family produced a mul- titude of artists of the first rank. ... Its head was Weit Bach, a baker of Presburg, who used to seek relaxation from labor in music and song. He had two sons, who commenced that unbroken line of mu- sicians of the same name that for nearly two centuries overran Thuringia, Saxony, and Franconia. . . . They were all organists or church-singers. ... In this fam- ily are reckoned twenty-nine eminent musicians." ' The feeding quality, or tendency to lay on fat, which is one of the most important characteristics of the meat-producing breeds of animals, is also heredi- tary. In each distinctive breed, where the production of meat is the leading quality, there are certain fami- lies that excel in this direction. It has been claimed that the predisposition to obesity is so strong in many cases that it is observed * " Horse Portraiture," by Simpson, p. 303. « Ribot on " Heredity," p. 63 ; Carpenter's " Mental Physiology," p. 273. 16 PEINCIPLES OF STOCK-BREEDDsc^. even under the disadvantages of privation and hard labor. ^ The duration of the life of an individual is deter- mined, to a great extent at least, by inheritance. The members of some families die at an early age, while in other families a ripe old age may be reasonably expect- ed. The life-tables that have been constructed show the average expectation of life of the masses ; while the expectation of life of an individual can only be approxi- mately determined by the age attained by his ancestors. Darwin mentions " the case of four brothers who died between the ages of sixty and seventy, in the same highly-peculiar comatose state.' . . . " It is now generally understood that longevity depends far less on race, climate, profession, mode of life, or food, than on hereditary transmission." There are long-lived families under what would be considered unfavorable conditions for longevity, while other families are short-lived under the most favorable conditions for the promotion of health. " The aver- age of life," says Dr. Lucas, "plainly depends on locality, hygiene, and civilization, but individual lon- gevity is entirely exempt from these conditions. Everything tends to show that long life is the result of an internal principle of vitality, which privileged individuals receive at their birth. It is so deeply im- printed in their nature as to make itself apparent in every part of the organization." ' ^ " Heredity," by Ribot, p. 3 ; Colin, " Physiologic Comparee," tome ii., p. 534. ^ "Animals and Plants under Domestication," vol. ii., p. 28. ^"Heredity," by Ribot, p. 5; Smith's "Physical Indications of Longevity," p. 3. HEREDITY OF NORMAL CHARACTERS. 17 The remarkable difference tliat is observed in the fecundity, not only of individuals but of classes and families, is undoubtedly owing to inherited peculiari- ties of the system. As a rule, the lower groups of animals present a greater activity of the reproductive powers than the higher. Among the vertebrates the oviparous classes are more prolific than the viviparous. Certain families are noted for their fecundity, while in others it is rare to find an individual that has many descendants. Girou relates the case of a mother who gave birth to twenty-four children, among them five girls, who in turn gave birth to forty-six children in all. The daughter of this woman's son, while still young, gave birth to her sixteenth child. In some families inherited fecundity has been ob- served for five or six generations. " The sons, daugh- ters, and grandchildren, of a couple who were the parents of nineteen children, were nearly all gifted," says Lucas, " with the same fecundity." * Those familiar with the various breeds of domestic animals will call to mind many cases that illustrate the heredity of the procreative powers. Of the high-bred families of the improved breeds, some are remarkably prolific, while others are almost uniformly deficient in this important quality. The imported Short-horn cow. Young Mary, by Jupiter (2170), had fourteen heifer-calves and one bull, and died at the age of twenty-one years. Her offspring were almost without exception re- 1 " Heredity," by Ribot, p. 4 ; " Cyclopaedia of Anatomy and Physi- ology," vol. ii., p. 471. 2 18 PRINCIPLES OF STOCK-BREEDING. markably prolific. Mr. Lewis F. Allen, the editor of the " American Short-Horn Herd-Book," «ajs, " More herd-book pedigrees run to Young Mary than any- other half-dozen cows on record." ' It is generally admitted by physiologists that the mental peculiarities of an individual are determined, to a great extent, by hereditary influences. Dr. Carpenter says : " The view of the relation of mental habits to peculiarities of bodily organization, whether congenital or acquired^ must be extended to that remarkable hereditary transmission of psychical character which presents itself under circumstances that entirely forbid our attributing it to any agency that can operate subsequently to birth, and which it would seem impossible to account for on any other hypothesis than that the 'formative capacity' of the germ, in great degree, determines the subsequent de- velopment of the brain, as of other parts of the body, and (through this) its mode of activity. . . . And this formative capacity, which is the physiological expres- sion of what is commonly spoken of as the * original constitution' of each individual, is essentially deter- mined by the conditions, dynamical and material, of the parent organisms." ^ • In domestic animals it is a matter of common ob- servation that the temper or disposition, and other mental peculiarities of individuals, are determined ^ " History of Short-Horns," p. 217. For further illustrations, see the chapter on " Fecundity." "^ " Mental Physiology," pp. 367, 368 ; " Cyclopaedia of Anatomy and Physiology," vol. ii., p. 471 ; Carpenter"'s " Human Physiology," p. 817. Ribot, in his work on " Heredity," gives an extended discussion of the hereditary transmission of mental peculiarities. HEREDITY OF NORMAL CHARACTERS. 19 by inheritance. The peculiar imperfection of vision manifested in the inability to distinguish colors — popularly known as color-blindness — is also hereditary. Of the many instances on record of the hereditary transmission of this defect, the following is perhaps the most remarkable. Dr. Pliny Earle says: "My maternal grandfather and two of his brothers were characterized by it, and among the descendants of the first-mentioned there are seventeen persons in whom it is found. I have not been able to extend my in- quiries among the collateral branches of the family, but have heard of one individual, a female, in one of them, who was similarly affected. . . . !N'othing is known of the first generation (of five) in regard to the power of the perception of colors. In the second, of a family consisting of seven brothers and eight sisters, three of the brothers — one of whom, as before men- tioned, was the grandfather of the writer — ^had the defect in question. In the third generation, consist- ing of the children of the grandfather aforesaid, of three brothers and four sisters, there was no one whose ability to distinguish colors was imperfect. In the fourth generation, the first family includes five brothers and four sisters, of whom two of the former have the defect. In the second family there was but one child, whose vision was normal. In the third there were seven brothers, of whom four had the defect. In the fifth, seven sisters and three brothers, of all of whom the vision is perfect in regard to color. In the sixth, four brothers and ^yq sisters, of whom two of each sex have the defect. In the seventh, two brothers and three sisters — ^both of the 20 PRINCIPLES OF STOCK-BREEDING. former have the defect. In the eighth there was no issue, and in the ninth there are two sisters, both of them capable of appreciating colors. Of the fifth generation, the defective perception has hitherto been detected in but two of the families. In one of them, consisting of three brothers and three sisters, one of the brothers has the defect, and in the other, a male, an only child, is similarly affected." * The peculiar condition of the lens of the eye ob- served in short-sighted people is hereditary, as is also the opposite defect, giving what is known as long sight." " Day-blindness, or imperfect vision under a bright light, is inherited, as is night-blindness, or an inca- pacity to see except under a strong light. A case has been recorded by M. Currier of this latter defect having affected eighty-five members of the same fam- ily during six generations." ' Dr. Earle likewise gives the case of a family in which a defective musical ear is associated with an imperfect appreciation of colors. In a family of my acquaintance a peculiarity in the walk is hereditary. Hibot says that in some families the hair turns gray in early youth, and similar cases have come under my own observation. The loss of the teeth, when a particular age is * American Journal of the Medical Sciences, vol. xxxv., p. 347 ; quoted in " Cyclopaedia of Anatomy and Physiology," vol. iv., p. 1453. ^ Darwin, " Animals and Plants under Domestication," vol. ii., p. 17. ' Darwin, loc. cit, vol. ii., pp. 19, 269. HEREDITY OF NORMAL CHARACTERS. 21 reached, is also an hereditary character in many fami- lies. Without a further enumeration of details, it may be said that every peculiarity of the animal organiza- tion is influenced by heredity. CHAPTEE III. HEEEDITY OF DISEASES. Ant abnormal peculiarities of the animal organi- zation, constituting disease, whether of structure or function, are liable to be transmitted from parent to offspring. When a disease is characterized bj obvious struct- ural changes in any part of the system, its heredity is seldom called in question ; but when it consists in a simple derangement of function, without any apparent indications of structural transformation, its hereditary character is frequently overlooked. As the progress of physiological science, however, makes us better acquainted with the minute structure of the various organs of the body, and the relations of such structure to their activity, the cases of functional disturbance that are not known to be accompanied by correspond- ing changes in structure have rapidly diminished, and that to so great an extent that it seems probable that aU indications of disease are the result of some struct- ural modification of the organs involved. The hereditary transmission of some peculiarity in the performance of the function of an organ, without apparent structural change, is perhaps not more diffi- cult to understand than the heredity of habits that, in HEREDITY OF DISEASES. 23 themselves, are not beneficial. It may, in fact, be said that any peculiarity in tbe functional activity of an organ, if long continued, may result in a babit of tbe system which the offspring will in aU probability inherit. Hereditary disease may make its appearance at the time of birth, when it is said to be congenital, or a considerable length of time may elapse before any indications of its presence are observed. In the latter case 2i predisposition or tendency to the disease is said to be inherited, which often requires some external exciting cause for its full development.* There are certain diseases that are transmitted with greater uniformity than others ; yet a predispo- sition to almost every known form of disease is likely to become hereditary, even if the influence that deter- mines its transmission is not sufficiently intense to render it congenital. It is not my purpose to describe or even enumerate aU the diseases that are known to be hereditary, but to notice only those that illustrate the laws of hereditary transmission, or that, from their frequent occurrence, are of particular interest to breeders of domestic animals. Under the general term "scrofula," a great variety of disorders are in- cluded, all of which are characterized by a perversion of the nutritive functions, and the formation of pe- cuhar tumors, called tubercles, in the various organs of the body. The most common forms of scrofulous ^ Adams on "Hereditary Diseases," p. 19; Williams's "Principles of Medicine," p. 4*7; Paget's "Surgical Pathology," p. 514; "Cyclo- paedia of Anatomy and Physiology," vol. ii., p. 471 ; Aitken's " Science and Practice of Medicine," voL ii., p. 35. 24 PRINCIPLES OF STOCK-BKEEDING. affections are consumption, mesenteric disease, diar- rhoea, dysentery, hydrocephalns, and glandular swell- ings, the symptoms varying with the organs affected/ Scrofulous diseases are of common occurrence in horses, cattle, sheep, and swine, either in a congenital form, or as a predisposition that may be actively de- veloped at any period of life. In treating of the he- reditary diseases of cattle, Finlay Dun remarks that " a tendency to consumption and to dysentery is often indicated by certain well-marked signs. In cattle the most obvious of these are a thin and often appar- ently long carcass, narrow loins and chest, flat ribs, undue length between the prominence of the ilium and the last ribs, giving a hollow appearance to the flanks, extreme thinness and fineness of the neck and withers, hoUowness behind the ears, fullness under the jaws, a small and narrow muzzle, . . . hard, un- yielding skin, . . . thin and dry hair, irregularity in the changing of the coat, inaptitude for fattening, prominence of the bones, especially about the haimch and tail, and want of harmony among the different parts of the body, giving the animal a coarse and un- gainly look — appearances all indubitably hereditary, and indicative of a weak and vitiated constitution, and of a decided scrofulous diathesis." ' The peculiarities enumerated are all indications of ' For a more extended description of this class of diseases the fol- lowing authorities may be consulted : Journal of the Royal Agricult- ural Society^ vol. xiy., p. 124, vol. xv., pp. 79, 82, voL xvi., p. 21, etc. ; Aitken's "Science and Practice of Medicine," vol. ii., p. 215; Gross's " System of Surgery," vol. i., p. 264 ; and other standard medical works. ^ Journal of the Royal Agricultural Society^ vol. xv., p. 82. HEREDITY OF DISEASES. 25 defective nutrition, which is one of the most marked characteristics of the disease. The same characters, with but little variation, are also indicative of the scrofulous habit in horses, sheep, and swine/ In the heredity of scrofula, it appears that the constitutional defect is readily transmitted ; but it may present itself in a different form from that ob- served in the generations immediately preceding. If the lungs are affected in one generation, the inherited predisposition of the next may consist in a tendency to glandular swellings, mesenteric disease, or some * In March, 1882, Dr. Koch made public his important discovery that the cause of scrofula (tuberculosis) was a microscopic, rod-like parasite (bacillus), which could be transferred from one animal to an- other, and thus communicate the disease. In the congenital form of hereditary scrofula the disease may therefore be directly communi- cated by the parents to their offspring by means of this specific con- tagium, which may be conveyed in the mother's milk, or even in the exhalations from the lungs. When the disease appears later in life, the inherited tendency to the disease consists in the transmitted con- stitutional defects of the parents, which act as predisposing causes, by rendering the system peculiarly susceptible to the influence of the spe- cific tubercle-bacillus communicated by diseased animals. Aside from this inherited tendency, the most potent predisposing causes of scrofula are protracted disorder of the digestive organs, food deficient in qual- ity and quantity, impure water, confinement in dark, damp, filthy, crowded, and unventilated apartments, exposure to cold, or any other condition that lowers the vital powers. When a predisposition to scrofula is inherited, these conditions will be intensified in their action as predisposing causes of the disease. According to Dr. Aitken (" Practice of Medicine," vol. ii., p. 234), " the domesticated animal is more liable to scrofulous disease than the same animal in a wild state. The stabled cow, the penned sheep, the tame rabbit, the mon- key, the caged lion, tiger, or elephant, are almost invariably cut off by scrofulous affections " — due, undoubtedly, to defective sanitary sur- roundings which predispose the system to the action of the specific ba- cillus of contagion. 26 PRINCIPLES OP STOCK-BREEDING. other scrofulous affection, while the tendency to lung- disease may make its appearance in the next or some subsequent generation. The same may be said of all so-called " constitu- tional diseases," the organ affected determining the character of the symptoms that indicate the presence of the general defect of the system. When the general constitutional predisposition is inherited, the conditions to which the animal is sub- jected as to food, exposure, etc., may have an influ- ence in determining the particular organ in which the disease is developed.* Dr. Gross says, " The children of consumptive par- ents are often cut off by the same disease, or they suffer in various parts of the body, as the bones and joints, lymphatic ganglions, eye, ear, and serous mem- branes." " In 1,000 cases of consumption tabulated by Dr. Cotton, 367 were hereditary, and of these the brothers or sisters were likewise affected in 126 cases. Of the 114: males whose parents were affected, 59 inherited the disease from the father, 40 from the mother, and 15 from both. Of the 127 females whose parents ^ The injudicious use of active medicines may also be mentioned as an efficient exciting cause of the development of a disease to which the animal is predisposed, and the organs subjected to the action of such medicines will in all probability become the seat of the affection. A severe cathartic, for example, may thus develop the hereditary tendency to chronic diarrhoea or dysentery ; or a profuse bloodletting may lower the general tone of the system, and thus favor the influence of other depressing agencies in developing the disease. ' "System of Surgery," vol. i., p. 265, See also Dr. Allen on "He- reditary Disease," p. 7. HEREDITY OF DISEASES. 27 were affected, 53 inherited the disease from the fa- ther, 62 from the mother, and 12 from both.* A comparison of .1,031 consumptives with 1,031 non-consumptives, insured in the Mutual Life In- surance Company of 'New York, shows that " nearly twice as many of the former had consumptive blood- relations as of the latter, or, to speak more accurately, 18.81 per cent, of the consumptives, and only 10.89 per cent, of the non-consumptives, had near relations (parents or brothers or sisters) who died of consump- tion." These " cases were all healthy lives, selected after medical examination, and one of the rules of this ex- amination tended to exclude persons with a decided family taint ; hence we should expect to find here a much smaller number of tainted families than among consumptives in general." ' The transmission of mental peculiarities, referred to in the preceding chapter, is not confined to those idiosyncrasies that are compatible with what may be termed a healthy condition of the nervous system, but extend also to the various forms of mental disease. Among 1,375 lunatics, Esquirol found 337 cases of hereditary transmission.' In 50 cases of insanity examined by Maudsley, 16 * " On the Nature, Symptoms, and Treatment of Consumption," by R. P. Cotton, M. D., London, 1852, p. 61 ; quoted in the Journal of the Royal Agricultural Society^ vol. xvi., p. 35. ' " Mortuary Experience of the Mutual Life Insurance Company of New York," vol. ii., pp. 71-73. ' Popular Science Monthly, November, 1873, p. 58 ; London Lancet, quoted in the Facijw Medical and Surgical Journal, February, 1877, p. 406. 28 PRINCIPLES OP STOCK-BREEDING. were hereditary. In T3 cases given bj Trelat, 43 are represented as due to heredity. " From a report made to the French Government in 1861, it appears that, in 1,000 cases of persons of each sex admitted to asy- lums, 264 males and 266 females had inherited the disease. Of the 264 males, 128 inherited from the father, 110 from the mother, and 26 from both. Of the 266 females, 100 inherited from the father, 130 from the mother, and 36 from both." ^ Dr. Hammond remarks that the hereditary ten- dency to insanity is shown " not only by the fact that ancestors have been insane, but that insanity in the descendants may have resulted from hysteria, epi- lepsy, catalepsy, or some other general nervous affec- tion in them." ^ Bone-spavin, curbs, ring-bone, navicular disease, and other similar affections of the bones and joints, are of frequent occurrence in the hereditary form. Many cases are on record illustrating the heredity of this class of diseases, which we need not quote, as the fact of their transmission is familiar to every one. But a single case will be given, that came under my observation several years ago. A mare affected with ring-bone, that unfitted her for farm-work, was kept as a breeder for several years. Her colts were quite uniform in form and color, and, as they showed no indications of the disease when two or three years old, they found ready buyers at good prices. At the age of five or six years, however, they all » Ribot, "Heredity," p. 131. * " Diseases of the Nervous System," p. 376. HEREDITY OF DISEASES. 29 had ring-bone, to a greater or less extent, and several were entirely disabled. In horses, strain of the back-tendons, swelled legs, grease, and roaring, are often hereditary ; while a pre- disposition to rheumatism, malignant and non-malig- nant tumors, chronic cough, ophthalmia and blind- ness, epilepsy, and a great variety of nervous disorders, is inherited by them in common with cattle, sheep, and swine.^ Lucas says, " A blind beggar was the father of four sons and a daughter, all blind. Dufau, in his work on ^ BKndness,' cites the cases of twenty-one persons bhnd from birth, or soon after, whose ancestors — ^fa- ther, mother, grandparents, and uncles — ^had some serious affection of the eyes." ^ According to M. Trehonnais, a stallion, in France, became blind from the effects of disease, and all of his progeny had the same defect before reaching the age of three years.^ Dr. Dun says that " a very large number of the stock of the celebrated Irish horse Cregan have be- come affected by ophthalmia of the worst kind. I am told by a gentleman well acquainted with this stock that the tendency is still decidedly marked, even in the fourth and fifth generations, often appearing, and sometimes speedily causing blindness very early * " Encyclopedie Pratique de I'Agriculteur," tome viii., p. 678. See also a series of articles on " Hereditary Diseases," by Finlay Dun, in the Journal of the Royal Agricultural Society^ vols, xiv., xv., xvi. ' Quoted from Ribot on " Heredity," p. 40. See also Darwin's "Animals and Plants imder Domestication," vol. ii., p. 18. 2 " Encyclopedie Pratique de I'Agriculteur," tome viii., p. 678. See also " The Horse," by Youatt, p. 115. 30 PRINCIPLES OF STOCK-BREEDING. in life, as at two or three years of age, and even be- fore the animals have been exposed to what are con- sidered the ordinary exciting causes of ophthalmia." * M. Pauli gives the case of a family of nine chil- dren who were all bom blind. Sir Henry Holland states that four out of five children in one family be- came blind at the age of about twelve years, the he- reditary character of the defect being confirmed by " the existence of a family monument, long prior in date, where a female ancestor is represented with several children around her, the inscription recording that all the number were blind." " In the family of Le Compte, thirty-seven chil- dren and grandchildren became bhnd like himseK, and the blindness in this case occurred about the age of seventeen or eighteen years, for three successive generations." ^ Dr. Dun gives the case of a stallion that, at the age of four years, " appeared perfectly sound, and his limbs were nearly black, well formed, and fine ; with- in a short time, however, they became thick and greasy. And, although the mares to which he was put were perfectly free from such faults, the progeny have shown, in every case where they can be traced, unmistakable evidence of their inheriting the greasy diathesis of their sire. They have all been found liable to swelled legs when they stand idle for a few * Journal of the Royal Agricultural Society, vol. xiv., p. 120. ' The last three cases are copied from Mr. Sedgwick's paper in the British and Foreign Medico- Cldrurgical Review, April, 1861, p. 250. The case of the Le Compte family was originaUy reported in the 30111- more Medical and Physical Register, 1809. HEREDITY OF DISEASES. 31 days ; most of them have been the subjects of repeat- ed attacks of weed ; all are affected, particularly in the spring, with scurfiness of the skin of the hind ex- tremities, and excessive itchiness, and lose at a very early age their flatness and smoothness of limb." " The faults occur, to a greater or less degree, in all the stock of this horse by many different mares, and are distinctly traceable to the third generation." ^ The following case c^ bilateral symmetry in the heredity of bony tumors, reported by Dr. Paget, is of particular interest, as it illustrates a peculiarity which is also observed in other diseases : " A boy, six years old, was in St. Bartholomew's Hospital, five years ago, who had symmetrical tumors on the lower ends of his radii, on his humeri, his scapulae, his fifth and sixth ribs, his fibulae, and internal malleoli. On each of these bones, on each side, he had one tumor, and the only deviations from symmetry were that he had an unmatched tumor on the ulnar side of the first pha- lanx of his right forefinger, and that each of the tumors on the right side was rather larger than its fellow on the left. I saw this child's father, a healthy laboring-man, forty years old, who had as many, or even more, tumors of the same kind as his son ; but only a few of them were in the same positions. All these tumors had existed from his earliest childhood ; they were symmetrically placed, and ceased to grow when he attained his f uU stature ; since that time they had undergone no apparent change. None of this man's direct ancestors, nor any other of his children, had similar growths; but four cousins, one female * Journal of the Royal Agricultural Society^ vol. xiv., p. 122. 32 PRINCIPLES OP STOCK-BREEDING. and three male children of his mother's sisters, had as many of them as himself." ^ The inherited predisposition to any form of dis- ease may be derived from either or both parents, but, in the latter case, it is also likely to be intensified by being made a dominant character." The hereditary predisposition to disease may not be observed in a particular individual, but its recur- rence in the offspring shows that the defect has been inherited, and likewise transmitted. In such cases the influence of favorable sanitary conditions may have been sufficient to counteract the inherited ten- dency in some degree, or the absence of exciting causes may have prevented its development, with- out interfering with the potency of its transmission to the next generation. The hereditary predispo- sition may thus be suspended for several genera- tions, and then reappear with an intensity that in- dicates the marked persistence of the hereditary taint, even in individuals that seem to be exempt from it. The inherited predisposition to disease, in indi- viduals apparently free from it, may often be detected by its repeated occurrence in some collateral branches of the family. This alternation in the development of hereditary disease is observed, not in rare instances only, but so frequently that it seems to be the rule, ^ " Surgical Pathology," p. 465. '^ " Cyclopaedia of Anatomy and Physiology," vol. ii., p. 4Y1 ; Car- penter's " Mental Physiology," p. 369 ; London Lancet, quoted in the Pacific Medical and Surgical Journal, February, 1877, p. 408. (For dominant characters see pp. 77 and 78.) HEREDITY OF DISEASES. 33 rather than the exception, in the transmission of con- stitutional peculiarities. In speaking of the heredity of cancer, Dr. Paget says : " Let it be ohserved, this tendency to cancerous disease is most commonly derived from a parent who is not yet manifestly cancerous ; for, most commonly, the children are bom before cancer is evident in the parent; so that, as we may say, that which is still future to the parent is transmitted potentially to the offspring. iN^ay, more, the tendency which exists in the parent may never become in him or her effective, although it may become effective in the offspring; for there are cases in which a grandparent has been cancerous, and, although his or her children have not been so, the grandchildren have been. Let me repeat, the cases of hereditary cancer only illustrate the com- mon rule of the transmission of hereditary properties, whether natural or morbid. Just as the parent, in the perfection of maturity, transmits to the offspring those conditions, in germ and rudimental substance, which shall be changed into the exact imitation of the parent's self, not only in the fullness of health, but in all the infirmities of yet future age ; so, also, even in seeming health, the same parent may communicate to the materials of the offspring the rudiments of yet future diseases ; and these rudiments must, in the case before us, be such modifications of natural composi- tions as, in the course of many years, shall be devel- oped or degenerate into materials that will manifest themselves in the production of cancer." ' Li the cases of hereditary disease already noticed, 1 " Surgical Pathology," p. 639. 34: PRINCIPLES OF STOCK-BREEDING. the defect in the system of the ancestors is apparently transmitted directly to the offspring, where it makes its appearance in the congenital form or as a predis- position. Animals that are, however, free from constitu- tional taint, may transmit indirectly to their offspring a predisposition to certain forms of disease, through a faulty conformation or proportion of the organization, that can hardly be considered abnormal. Animals inheriting such peculiarities of structure may remain healthy under favorable conditions ; but they are liable to disease, from the effects of exposure or hard work, that would not be injurious to those with a better-proportioned organization. According to Finlay Dun, a disproportion in the width and strength of the leg below the hock to the width and strength above the hock, predisposes to spavin ; a straight hock and a short os calcis, inchn- ing forward, gives a tendency to curbs ; " round legs and small knees, to which the tendons are tightly bound, are especially subject to strains ; " while a pre- disposition to navicular disease is found "in horses with narrow chests, upright pasterns, and out-turned toes." ' "Many farm -horses, as well as others without much breeding, are remarkable for consuming large quantities of food, for soft and flabby muscular sys- tems, and for round limbs containing an unusual pro- portion of cellular tissue. These characters are no- toriously hereditary, of which indubitable evidence is afforded by their existence in many different indi- * Journal of the Royal Agricultural Society ^ vol. xiv., p. 115. HEREDITY OP DISEASES. 35 viduals of the same stock, and their long continuance, even under the best management and most efficient systems of breeding. Such characters indicate pro- clivity to certain diseases, as swelled legs, weed, and grease." ^ If the leg below the hock is disproportionately long, and the os calcis is short (giving a narrow hock), a strain of the joint, or some other form of disease, is liable to result from an amount of work that would not be severe in a limb of proper proportions. Any marked dilatation or contraction of the blood- vessels gives a tendency to irregularities of the circu- lation when the work performed is severe, and a con- sequent predisposition to congestion or inflammation of important organs. Like an engine with a fly-wheel that is not per- fectly balanced, the animal organization of faulty pro- portions is enabled to perform a moderate amount of work without difficulty ; but, when the machinery is taxed nearly to its full capacity, the defective adjust- ment becomes a source of danger, involving the in- tegrity of other parts of the system. This indirect transmission of a predisposition to disease, through a faulty proportion of parts, is of frequent occurrence, and it will undoubtedly explain many of the cases of disease appearing suddenly, without apparent cause, and in which an heredi- tary taint was not suspected, from the fact that the ancestors were not affected with the disease in any form. This form of hereditary transmission furnishes a * Journal of the Royal Agricultural Society^ vol. xiv., p. 121. 36 PRINCIPLES OF STOCK-BREEDING. good illustration of the importance, to the breeder, of a knowledge of all the details of structure and confor- mation of the animal system, and the relations of pecuharities of form to strength and constitutional vigor. The offspring of animals that are very young, with a system immature or imperfectly developed, or of those that have had their constitution impaired by abuse or overwork, will inherit a condition of the sys- tem that predisposes to attacks of disease from slight exciting causes. The effects may not be observed in all cases in a single generation, but, if the practice of breeding from such imperfect organizations is continued for several successive generations, the most unfavorable results may be produced. It is stated that "jprecocious marriages are not only less fertile, but the children also which are the result of them have an increased rate of mortality." ^ Dr. Duncan adds " the evidence of two gentlemen skilled in the breeding of lambs and calves. They say that the mortality of the young of these animals, when the mothers are immature, is much greater than when they are well grown." " One of them says : ' Taking the first lamb from ewes at one year old has in almost every case failed to be remunerative, owing to the frequent death of the lambs.' The same may be said of young heifers, though the mortality of the offspring may not be so marked as in that of sheep." ^ ^ Dr. Duncan, " Fecundity, Fertility, and Sterility," p. 38. s Ibid., p. 390. HEREDITY OF DISEASES. 37 The same author says : " Childbearing by an im- mature mother is popularly held to be dangerous to the continued general health of the mother, and to prevent her complete development in size and beauty. I have no positive evidence to adduce in favor of this generally-entertained notion, which my own experi- ence appears to me to confirm. ... In its corrobora- tion, however, I can adduce the ample experience of eminent breeders of the lower animals. I have had this opinion expressed to me, especially in regard to mares, cows, ewes, and bitches." * Many other authorities might be cited to the same effect, were it not that the influence of early breeding in arresting the development of the mother is so often observed by intelligent breeders as to render it unne- cessary. In oviparous animals it has been observed, not only that the eggs of very young females are less in number and smaller than those produced at maturity, but that a larger proportion are not fertile, the yelk being frequently wanting or imperfect. And also, in other groups of animals, that the number of young produced at a birth is less with young mothers than with those that are fully developed.* GeyeKn says : " It has been ascertained that the ovarium of a fowl is composed of six hundred ovules, or eggs; therefore a hen, during the whole of her life, cannot possibly lay more eggs than six hundred, which, in a natural course, are distributed over nine years, in the following proportions : ^ Dr. Duncan, " Fecundity, Fertility, and Sterility," p. 392. 2 Ibid., pp. 38, 65, '70. 38 PRINCIPLES OF STOCK-BREEDING. *' First year after birth Second " (( u Third " u u Fourtli " u u Fifth " u a Sixth " (( u Seventh " (< u Eighth » a a Einth " U (( 15 to 20 00 u 120 20 u 135 00 u 115 60 a 80 50 u 60 35 (( 40 15 u 20 1 (( 10 »» Dr. Duncan, in summing up the results of an ex- tended collection of statistics relating to births, shows that a similar law prevails among women. While those under twenty years of age are less fecund than those between twenty and twenty-four, a gradual in- crease in productiveness is made to the age of thirty years, which is the most prolific age, after which a rapid decrease in fertility takes place.'' The influence of diminished fecundity in young mothers upon their offspring, that necessarily inherit tlie same peculiarity, would tend to predispose to bar- renness and sterility in the breed or family in which early breeding is frequently practised ; while the de- fective development of the mother, arising from the same cause, would become a constitutional peculiarity in the offspring. As the retarded development of the mother and the defective condition of the germ or egg are both the result of immaturity, and a consequent deficiency in constitutional vigor, which, as we have seen, will undoubtedly be transmitted, they must have a marked * " Poultry-Breeding," p. 27. ' Dr. Duncan, " Fecundity, Fertility, and Sterility," as quoted in Walford's "Insurance Cyclopeedia," vol. iii., p. 194. HEREDITY OF DISEASES. 39 influence in producing conditions of the system that predispose to disease/ ^ In addition to authorities quoted, see Duckham's " Lecture on Hereford Cattle," p. 5; Youatt on "Cattle," p. 626; Youatt on "The Horse," p. 221. According to the observations of Livingston Stone on the McCloud River, California, " 14,000,000 eggs obtained from ripe but relatively young and smaller salmon were, without exception, at least one-third smaller than the millions of eggs which were before ob- tained from older, larger salmon of the same species." (" Fisheries Report," 1878 ; " Nature," xxvii., p. 303.) CHAPTEE TV. HEEEDITT OF ACQUIRED AND ABNOEMAL CHAEACTEES. The habits and characteristics of animals that have been developed by the conditions in which they are placed, or the peculiar training they have received at the hands of man, appear to be transmitted from gen- eration to generation, with nearly the same certainty and nnif ormity as those that characterize the original type or species from which they are descended. Some of the most striking illustrations of this form of heredity are to be found in the transmission of the highly-artificial peculiarities that characterize the vari- ous improved breeds of animals. The tendency to lay on fat rapidly and to mature early is inherited in the best families of the Short-horns — ^the Devons, the Herefords, and other meat-producing breeds — while the ability to secrete an abundant supply of milk is, in like manner, perpetuated in the Ayrshires, the Jer- seys, and other dairy breeds. The certainty with which these acquired qualities are transmitted constitutes one of the most valuable peculiarities of a breed. The American trotting -horse furnishes another illustration of the inlieritance of acquired characters. The various breeds of dogs have peculiarities that ACQUIRED AND ABNORMAL CHARACTERS. 41 have been developed bj a long course of training, wbich are transmitted with a nniformity that is sur- prising. Young setters, pointers, and retrievers, that have never been in the field, will often " work " with as much steadiness and ability as those that have had a long experience in sporting. In such cases, however, it will be found that the ancestors, immediate or remote, have been well trained in their special methods of hunting. The shepherd-dog is remarkable for its sagacity and the persistence with which it carries out the wishes of its master ; and it would be difficult, if not impossible, to train dogs of any other breeds to equal them in their special duties. The greyhound runs by sight, and the blood-hound by scent, and their offspring all inherit the same peculiarities. " The curious fact was observed by Mr. Knight, that the young of a breed of springing spaniels which had been trained for several successive generations te find woodcocks seemed to know as well as the old dogs what degree of frost would drive the birds to seek their food in unfrozen springs and rills." ^ " A new instinct has also become hereditary in a mongrel race of dogs employed by the inhabitants of the banks of the Magdalena almost exclusively in hunting the white-lipped peccary. The address of these dogs consists in restraining their ardor and at- taching themselves to no individual in particular, but keeping the whole in check. ITow, among these dogs some are found which, the very first time they are taken to the woods, are acquainted with this mode of * Carpenter's " Mental Physiology," p. 104. 3 42 PRINCIPLES OF STOCK-BREEDIXG. attack, whereas a dog of another breed starts forward at once, is surrounded by the peccaries, and, whatever may be his strength, is destroyed in a moment." ^ '' A race of dogs employed for hunting deer in the platform of Santa Fe, in Mexico, is distinguished by the peculiar mode in which they attack their game. This consists in seizing the animal by the belly and overturning it by a sudden effort, taking advantage of the moment when the body of the deer rests only upon the forelegs, the weight of the animal thus thrown being often six times that of its antagonist. E'ow, the dog of pure breed inherits a disposition to this kind of chase, and never attacks a deer from before while running ; and even should the deer, not perceiving him, come directly upon him, the dog steps aside, and makes his assault upon the flank. On the other hand, European dogs, though of superior strength and general sagacity, are destitute of this instinct, and, for want of similar precautions, they are often killed by the deer on the spot, the cervical vertebrae being dislocated by the violence of the shock."' Mr. Lewes "had a pnppy taken from its mother at six weeks old, who, although never taught to ' beg * (an accomplishment his mother had been taught), spontaneously took to begging for everything he wanted, when about seven or eight months old ; he would beg for food, beg to be let out of the room, and one day was found opposite a rabbit-hutch, ^ " Cyclopaedia of Anatomy and Physiology," vol. iv., p. 1303 ; Car- penter's " Comparative Physiology," p. 627. * " Cyclopaedia of Anatomy and Physiology," vol. iv., p. 1303. ACQUIEED AND ABNORMAL CHARACTERS. 43 apparently begging the rabbits to come out and play." ■ A dog, owned by myself several years ago, inher- ited the same accomplishment from his mother, who had been trained to sit in an erect position and hold a stick in imitation of a soldier with a musket. This dog was taken from his mother when but a few days old, and before it had an opportunity of learning any tricks by imitation. Without any train- ing, when a few months old, he assumed the erect position whenever anything was wanted, and, if that did not attract attention, he would " speak," with a short bark, as his mother had been in the habit of doing. Dr. H. B. Shank, of Lansing, informs me that a cat, owned by him, had learned to open doors that were secured with a latch, and all of her descendants inherited the same peculiarity ; while another family of cats, brought up with them, did not learn the trick, although they had sufficient intelligence to ask the assistance of their more expert friends when they wanted a door opened. Girou de Buzarringues reports the frequently- quoted case of " a man who had the habit, when in bed, of lying on his back and crossing the right leg over the left. One of his daughters had the same habit from birth, and constantly assumed that position in the cradle." ' Darwin reports the interesting case of a boy who "had the singular habit, when pleased, of rapidly * Herbert Spencer, " Principles of Biology," vol. i., p. 247 ; Goodale, "Principles of Breeding," p. 26. 3 Quoted from Ribot on " Heredity," p. 8. 44 PRINCIPLES OF STOCK-BREEDING. moving his fingers parallel to each other, and, when mnch excited, of raising both hands, with the fingers still moving, to the sides of his face on a level with the ejes ; this boy, when almost an old man, could hardly resist this trick when mnch pleased, but, from its ab- surdity, concealed it. He had eight children. Of these a girl, when pleased, at the age of four and a haK years moved her fingers exactly in the same way, and, what is still odder, when much excited she raised both her hands, with her fingers still moving, to the sides of her face, in exactly the same manner as her father had done, and sometimes still continued to do when alone." * The handwriting of members of the same family is said to frequently present a marked resemblance ; "and it has been asserted that English boys, when taught to wi'ite in France, naturally cling to their English manner of writing." ^ " There are families in which the special use of the left hand is hereditary. Girou mentions a family in which the father, the children, and most of the grandchildren, were left-handed. One of the latter betrayed its left-handedness from earliest infancy, nor could it be broken of the habit, though the left hand was bound and swathed." ' Dr. Eugene Dupuy states that "he owed to his friend Dr. Gibney the opportunity of observing a family consisting of father and mother, ^yg children, and one grandchild. * "Animals and Plants under Domestication," vol. iL, p. 16. ' Ibid. ; Ribot on "Heredity," p. 9. 'Ibid., p. 38. ACQUIRED AND ABNORMAL CHARACTERS. 45 " The father and mother were semi-ambidextrous. All the children and the grandchild are ambidextroiis to an annoying degree ; all of the movements which they perform with one hand are simultaneously per- formed by the other hand. The girls are obliged to use only one hand when dressing themselves, or when cutting patterns, and hold the other hand down by their side, because the two hands perform the same movements at the same time, and would interfere with each other. " Attention was called to the fact that the father of the grandchild is not semi-ambidextrous. "Dr. Dupuy has made experiments upon these persons, and has found that, if the skin of the fore- arm on one side be kept well dry, and a rapidly-inter- rupted electrical current be used, so as only to call forth reflex actions, it is possible to induce synchro- nous movements in the fingers of both hands, and also muscular contraction in the lumbricales muscles of the fingers, which are too rapid to be carried on by the will."* Wild animals, living on islands not often visited by man, do not fear him, but allow the closest ap- proach without hesitation. "When the Falkland Islands were first visited by man, the large, wolf -like dog {Canis antarcticics) fear- lessly came to meet Byron's sailors, who, mistaking this ignorant curiosity for ferocity, ran into the water to avoid them. Even recently, a man, by holding a piece of meat in one hand and a knife in the other, ^ " Proceedings of the American Neurological Association," in the Virginia Medical Monthly, August, IS*?*?, p. 392. 46 PRINCIPLES OF STOCK-BREEDING. could sometimes stick them at night. On an island in the sea of Aral, when first discovered by Butakoff, the saigak antelopes, which are ' generally very timid and watchful, did not fly from us, but, on the con- trary, looked at us with a sort of curiosity.' " So, again, on the shores of the Mauritius, the manatee was not, at first, in the least afraid of man, and thus it has been in several quarters of the world with seals and the morse. I have shown elsewhere how slowly the native birds of several islands have acquired and inherited a salutary dread of man; at the Galapagos Archipelago I pushed, with the muzzle of my gun, hawks from a branch, and held out a pitcher of water for other birds to alight on and drink. " Quadrupeds and birds which have seldom been disturbed by man, dread him no more than do our English birds, the cows, or horses, grazing in the fields."^ Dr. Kidder, in his description of the " sheath-bill " {CMonis minor\ on Kerguelen Island, says, "When I sat down upon a rock and kept perfectly still for a few moments, they crowded around me like a mob of street boys around an organ-grinder," and " all seemed perfectly fearless and trustful." ^ That the descendants of such animals, inheriting the accumulated experience of their ancestors, become wild, is shown in the instinctive dread of man exhib- ited by the young of the same and allied species that are frequently brought into contact with him. G. * Darwin's " Animals and Plants under Domestication," vol. i., p. 33 ; Carpenter's " Mental Physiology," p. 90. * The Popular Science MontMy, April, ISYe, p. 661. ACQUIRED AND ABNORMAL CHARACTERS. 47 Leroy observes that " in districts where a sharp war is waged against the fox, the cubs, on first coming out of their earths, and before they can have acquired any experience, are more cautious, crafty, and suspicious, than are the old foxes in places where no attempt is made to trap them." " Knight, who for sixty years devoted himself to systematic observation of this class of facts, says that during that time the habits of the English woodcock underwent great changes, and that its fear of man was considerably increased by its transmission through sev- eral generations. " The same author discovered similar changes of habit, even in bees." * The marked heredity of habits has led some mod- ern writers to claim that the instincts of animals are but the experiences of past generations, that are ac- cumulated and established through inheritance. Many of the most valuable characteristics of the various im- proved breeds of animals have been produced by the inheritance of habits of the system, arising from the conditions and treatment to which they have been subjected. The remarkable records recently made by the American trotting-horse are the result of training and inheritance." The dairy breeds of cattle inherit a marked func- ^ Ribot on " Heredity," p. 17. 2 The first trotting-match in America was made in 1818, for a stake of $1,000, against time. It was won by a horse called Boston Blue, in the then unprecedented time of three minutes (" The Horse in Amer- ica," by Herbert, vol. ii., p. 133). 48 PKINCIPLES OF STOCK-BREEDma tional activity of the lacteal glands, which is biit a modified habit of the system. Pritchard, in his " J^atural History of Man," states that the peculiar ambling pace to which the horses bred on the table-lands of the Cordilleras are trained, has, by inheritance, resulted in a " race in which the ambling pace is natural and requires no teaching." The ISTorwegian ponies, descended from animals that " have been in the habit of obeying the voice of their riders and not the bridle," are said to inherit the same peculiarity, so that it is difficult to break them to drive in the ordinary way.^ The habit of migration at particular seasons of the year is inherited, and I have often observed it in mal- lard ducks bred for several generations in a state of domestication. It must be admitted, however, that acquired habits are not in all cases hereditary, but it would be diffi- cult, perhaps, in the present state of our knowledge of the subject, to 'Q.x a Hmit to their inheritance, so far, at least, as a predisposition is concerned. Acquired habits and the original traits of animals appear to be conflicting elements in their constitution, either one of which may, from its intensity, predomi- nate in hereditary transmission. Pigs have been taught to point game and to per- form various tricks, but, in the hereditary transmission of their characters, " I^ature " has had a stronger in- fluence than " culture." ^ The last two statements are quoted from Goodale's " Principles of Breeding," p. 25. JSee also " Cyclopaedia of Anatomy and Physiology," vol. iv., p. 1313. ACQUIRED AND ABNORMAL CHARACTERS. 49 Carpenter, in discussing the heredity of acquired habits, says, " There seems to be reason to believe that such hereditary transmission is limited to acquired peculiarities which are simply modifications of the natural constitution of the race, and would not extend to such as may be altogether foreign to it." ^ From a practical point of view, however, the in- heritance of acquired characters, so far as they are of any value, is, fortunately, without any apparent limit. Abnormal characters are frequently hereditary, but they are not so likely to be transmitted as acquired habits that are in harmony with the original peculiari- ties of the animal. The following examples will sufficiently illustrate this form of inheritance : Gratio Kelleia, the Maltese, " was born with six fingers upon each hand, and a like number of toes to each of his feet." He " married when he was twenty- two years of age, and, as I suppose there were no six- fingered ladies in Malta, he married an ordinary five- fingered person. " The result of that marriage was four children : the first, Salvator, had six fingers and toes, like his father ; the second was George, who had five fingers and five toes, but one of them was deformed, showing a ten- dency to variation ; the third was Andre — he had five fingers and five toes, quite perfect ; the fourth was a girl, Marie — she had five fingers and five toes, but her thumbs were deformed, showing a tendency toward the sixth. These children grew up, and, when they came to adult years, they all married, and of course it 1 " Mental Physiology," p. 104. 50 PRINCIPLES OF STOCK-BREEDING. happened that they all married five-fingered and five- toed persons. ISTow let us see what were the results. Salvator had four children — they were two boys, a girl, and another boy — the first two boys and the girl were six-fingered and six-toed like their grandfather ; the fourth boy had only five fingers and toes. " George had only four children ; there were two girls with six fingers and six toes ; there was one girl with six fingers and five toes on the right side, and -B.Ye fingers and 'Q.Ye toes on the left side, so that she was half-and-haK. The last, a boy, had '&^ve fingers and five toes. The third, Andre, you will recollect, was perfectly well formed, and he had many children whose hands and feet were all regularly developed. "Marie, the last, who of course married a man who had only five fingers, had four children : the first, a boy, was born with six toes, but the other three were normal." ^ " In a paper contributed to the Edinburgh New Philosophical Journal^ for July, 1863, Dr. Struthers gives several cases of hereditary digital variations. Esther P , who had six fingers on one hand, be- queathed this maKormation along some lines of her descendants, for two, three, and four generations. A — — S inherited an extra digit on each hand and each foot, from his father; and C G ^ who also had six fingers and six toes, had an aunt and a grandmother similarly formed." ' A deficiency in the number of fingers, or in the number of the phalanges or joints of the fingers and * Huxley on " The Origin of Species," p. 92. ' Herbert Spencer's "Principles of Biology," vol. i., p. 243. ACQUIRED AND ABNORMAL CHARACTERS. 51 toes, may likewise be transmitted, as shown in the following cases from Mr. Sedgwick's paper on the " Influence of Sex in Hereditary Disease : " A pastry-cook at Donai, named Augnstin Dnforet, had but two phalanges to all his fingers and toes. This defect he inherited from his grandfather, who had three children with the same malformation ; the eldest of them (a son) had three sons all with the same defect ; the second (a daughter) has had ^ve children, two daughters with three phalanges, and three sons who have only two ; the third, who is the father of Augustin, had eleven children, ^Ye daughters normal- ly formed, and six sons, in all of whom there is a pha- lanx wanting in both fingers and toes. The mother of Augustin also had two male, still- born children, with the same deformity. Dr. Lepine reports the case of a man who had only three fingers on each hand, and four toes on each foot ; his grandfather and son had likewise the same deformity. Bechet records the case of a woman (Yictorie Barre) " who, instead of hands, had on each arm one finger only, the other fingers and their metacarpal bones, with the exception of imperfect rudiments of two of the latter, being entirely wanting ; while on each foot there were but two toes, apparently the first and fifth, but both very defective. She was twice married : by her first marriage she had a healthy and regularly-formed male child, and by her second mar- riage two daughters maKormed like herself ; and her sister and father were also deformed in a similar man- 52 PRINCIPLES OF STOCK-BREEDING. Another case is on record of the " hereditary ab- sence of the two distal phalanges," in which "the transmission of the defect for ten generations had been effected by the females only of the family." ^ A supernumerary organ, when inherited, may oc- cupy a different position from that observed in the parent, as in the case of a woman with three nipples, published by Adrien de Jussieu. " The additional nip- ple was placed in the groin, and served ordinarily for suckling, while in the mother of this woman, who was born also with three nipples, they were all placed on the anterior region of the thorax." ' The fifth toe of Dorking fowls, which is one of the characteristics of the breed, has been inherited, it is claimed, from a five-toed variety introduced into Britain by the Romans. Whether this is true or not, it is now impossible to determine, but the constancy of this peculiarity, even in the produce of other breeds crossed with the Dorking, would seem to indicate that it is a character which has been fixed by long-con- tinued inheritance.^ In the Houdan fowls, when first introduced into England from France, a fifth toe was rarely seen ; but at the present time it is nearly as constant in this breed as in the Dorkings.* Mr. "Wright says : " The abnormal structure of the Dorking foot is very apt to run into still more abnor- * British and Foreign Medico- ChirurgicalBeview, April, 1863, p. 460. 8 Ibid., July, 1863, p. 172. 3 Wright on "Poultry," pp. 311, 312; Darwin's "Animals and Plants under Domestication," vol. ii., p. 24. 4 Wright on " Poultry," p. 412. ACQUIRED AND ABNORMAL CHARACTERS. 53 mal forms, which, disqualify otherwise fine birds for the show-pen. Birds are not unfrequently produced which possess three back-toes, or have an extra toe high up on the leg ; or, in the case of the cock, with supernumerary spurs, which have been known to grow in every possible direction." * This tendency to an increase in the development of an abnormal character that has become hereditary has been observed in other cases, but we are as yet unable to present a satisfactory explanation of them. In the case of the Dorking, the practice of breeding only those birds that have the abnormal peculiarity might be expected to intensify the tendency to its production, by making it a dominant character ; but, in the following case given by Dr. Struthers, it will be safe to presume that only one parent had the ab- normal character, and yet we find the same tendency to its increase. " In the first generation an additional digit appeared on one hand, in the second on both hands, in the third three brothers had both hands, and one of the brothers a foot, affected ; and in the fourth generation all four limbs were affected." ' " In a family," says Sir H. Holland, " where the father had a singular elongation of the upper eyelid, seven or eight children were bom with the same de- formity, two or three other children having it not." ' Dr. Osborne reports the case of " John Murphy, » Wright on " Poultry," p. 331. * Quoted in Darwin's " Animals and Plants under Domestication," vol. ii., p. 23. ^"Philosophical Transactions," 1814, p. 91; quoted in Darwin's " Animals and Plants under Domestication," vol. ii., p. 17. 54 PRINCIPLES OF STOCK-BREEDING. aged fiftj-two years, a native of County "Wexford (Ireland), wlio had fifteen brothers and five sisters, all of whom possessed the family peculiarity of tortoise- shell-colored eyes. The inheritance was derived from the mother, whose maiden name was Murray. She had three sisters and one brother, who were all simi- larly affected, and who inherited the peculiarity from their mother, whose maiden name was F . It is to this latter family that the peculiarity belongs, inso- much that in the part of the country where they re- sided they have been commonly recognized by this distinction, and celebrated for communicating it to their posterity." In this case, for three generations "the transmission of the defect has been restricted exclusively to the female sex." * " In the year 1770, as we learn from D'Azara, a hornless bull was produced in Paraguay, which has been the progenitor of a race of hornless cattle that has since multiplied extensively in that country." ' The polled breeds of Great Britain undoubtedly had a similar origin. According to Dr. Bandall, " a ram having ears of not more than a quarter of the usual size appeared in a flock of Saxon sheep in Germany. He was a supe- rior animal, and got valuable stock. These were in- terbred, and a ' httle-eared ' sub-family created. Some of these found their way into the United States, be- tween 1824 and 1828. One of the rams came into * British and Foreign Medico- Chirurgical Review^ April, 1861, p. 248. The case was originally published in the Dublin Medical Journal for 1835. ' "Cyclopaedia of Anatomy and Physiology," vol. iv., p. 1311. ACQUIRED AND ABNORMAL CHARACTERS. 55 Onondaga County, 'New York. He was a choice ani- mal, and his owner, David Ely, valued his small ears as a distinctive mark of his blood. " He bred a flock by him, and gradually almost bred off their ears entirely. " His flock enjoyed great celebrity and popularity in its day, but has long been broken up, and many years have doubtless elapsed since any of the sur- rounding sheep-owners have used a ' little-eared ' ram ; yet nearly every flock that retains a drop of that blood — even coarse-mutton sheep bred away from it, prob- ably for ten or fifteen generations, insomuch that all Saxon characteristics have totally disappeared — still continues to throw out an occasional lamb as distinctly marked with the precise peculiarity under considera- tion as Mr. Ely's original stock." ^ The "Ancon" or "Otter" breed of sheep, that originated in Massachusetts in 1Y91, were character- ized by the length of their bodies and the " extreme shortness of the legs, which also turned out in such a manner as to render them rickety. They cannot run or jump, and even walk with difficulty." ' This deformed breed is said to be descended from » "Practical Shepherd," p. 104. * These sheep were described by Colonel Humphreys, in the " Philo- sophical Transactions," London, 1813, p. 88, according to Darwin ("Animals and Plants under Domestication," vol. i., p. 126), who states that this breed had their origin on the farm of Seth Wright, in Massa- chusetts. Chancellor Livingston, in his "Essay on Sheep," 1813, p. 37, from which the description above is quoted, says, " The Otter sheep, it is said, were first discovered on some island on our Eastern coast, where, I cannot precisely say, and from thence they have spread to the adjoin- ing States." 56 PRINCIPLES OF STOCK-BREEDING. a ram in which the malformation was congenital. It is stated, on the authority of Colonel Humphreys, that this defect became so fixed by inheritance that it was uniformly transmitted. The I^iata cattle, on the northern bank of the Plata, described by Darwin, have a pecuKar malfor- mation of the skull, that undoubtedly has been devel- oped by the inheritance of a deformity of some of the ancestors. In this breed "the forehead is very short and broad, with the nasal end of the skuU, together with the whole plane of the upper molar teeth, curved up- ward. The lower jaw projects beyond the upper, and has a corresponding upward curvature." * A very singular abnormal peculiarity is hereditary in some families of pigs — the tail, which is perfectly formed at birth, having a tendency to waste away and drop off when the animals are a few weeks old." Cases are reported of families with a single lock of hair of a different color from the rest of the hair, which in one generation may be upon the right side, and in the next on the left.^ A family of my acquaintance have several abnor- mal peculiarities that are transmitted with great uni- formity. The little toes lap over the adjoining toes, and the nails have a longitudinal groove that gives them a bifid termination, so that when the nail is trimmed the part cut off is in two pieces. This same character of the nail is seen also on the index-fingers. ^ "Animals and Plants under Domestication," vol. i., p. 113. ^ Journal of the Royal Agricultural Society^ vol. xvi., p. 41. * "Animals and Plants under Domestication," vol. ii., p. 14. ACQUIRED AND ABNORMAL CHARACTERS. 57 In addition to these peculiarities, a cartilaginous pro- jection on the back of the ear is inherited. The pa- ternity of an illegitimate child, in one instance, was traced to this family, from its inheritance of the pecu- liarities above-mentioned. Dr. Anderson says a gentleman of his acquaintance " chanced to find a rabbit among his breed that had only one ear ; he watched the progeny of that creature, and among these he found one of the opposite sex that had only one ear also ; he paired these two one-eared rabbits together, and has now a breed of rabbits with one ear only, which propagate as fast, and as steadily produce their like, as the two-eared rabbits from which they originally were descended." ^ The same author gives the case of a bitch that was born with only three legs. " She has had several lit- ters of puppies, and among these several individuals were produced that had the same defect with herself." ' He also states that " a cat belonging to Dr. Coven- try, of Edinburgh, which had no blemish at its birth, lost its tail by accident when it was young. " It has had many litters of kittens, and in every one of these there was one or more of the litter that wanted the tail, either in whole or in part." ' " Blumenbach afiirms that ' a man whose little- finger of the right hand had been nearly demolished and set awry had several sons, all of whom had the little fingers of the right hand crooked.' " * ^ " Recreations in Agriculture," vol. i., p. 68. 5 Loc, cit, p. 68. 3 ibid.^ p. 69. * As quoted in the British and Foreign Medico- Cliirurgical Review^ April, 1863, p. 462. 58 PRINCIPLES GF STOCK-BREEDING. In his experiments with Guinea-pigs, Dr. Brown- Sequard observed that, in those subjected to a particu- lar operation, involving a portion of the spinal cord or sciatic nerve, " a slight pinching of the skin of the face would throw the animals into a kind of epileptic convulsion. "When these epileptic Guinea-pigs bred together, their offspring showed the same predisposi- tion, without having been themselves subjected to any lesion whatever ; while no such tendency showed itself in any of the large number of young which were bred from parents that had not been operated on." ^ Prof. Tanner says he knew " a very striking in- stance of the loss of milk in a flock (previously cele- brated for their supply of milk) being traced entirely to the use of a very well-formed ram, bred from a ewe singularly deficient in milk." ^ It is stated on good authority that animals that have been " branded " in the same place for several successive generations, transmit the same mark to their oftspring." ' From the many cases of inherited habits and ab- normal peculiarities on record, we have quoted a suffi- cient number to show the great variety of such charac- ters that are liable to be transmitted. In a large proportion of cases it must be admitted that the abnormal peculiarities of parents are not ob- served in the offspring, and it has been claimed from ^ Carpenter's " Mental Physiology," p. 371 ; Darwin's "Animals and Plants under Domestication," vol. ii., p. 36 ; Herbert Spencer's " Biol- ogy," vol. L, p. 251. * Journal of the Royal Agricultural Society^ vol. xxii., p. 5. ' " Encyclopedic Pratique de I'Agriculteur," tome viii., p. 678 ; Goodale's " Principles of Breeding," p. 26. ACQUIRED AND ABNORMAL CHARACTERS. 59 this fact that they have not been transmitted. From the cases presented in the following chapter, however, it will readily be seen that the non-inheritance of a character can only be determined by an exhaustive ex- amination of the individuals in the collateral branches of the family, as well as those in the direct line of de- scent. If a character does not make its appearance in a particular instance, it does not necessarily follow that it has not been inherited, as it may be obscured or made latent by the presence of some other character that for the time is dominant in the organization. The heredity of acquired habits and abnormal pe- culiarities should not be considered as exceptional, but rather the result of some general law of the organiza- tion that is constant in its action, and the supposed cases of non-inheritance of a character will in all prob- ability be found to be in accordance with it. It has been supposed that the transmission of func- tional peculiarities of an organ involved the transmis- sion of some corresponding structural change of the organization, that gave rise to the abnormal modifica- tion of its function. There are cases, however, in which a well-marked functional derangement of certain organs, originally produced by an injury to the nervous system, has be- come hereditary, without the transmission of any ap- parent malformation of the nerves themselves. Dr. Eugene Dupuy has given some interesting illustrations of this singular form of heredity, some of which he observed as the assistant of Dr. Brown-Sequard, in his experiments on Guinea-pigs, already noticed, while others are the result of his own investigations. 60 PRINCIPLES OF STOCK-BREEDING. " If in a Guinea-pig, for instance," says Dr. Dupuy, "that portion of the vaso-motor branch (of nerves) which is in connection with the carotid artery in the neck — which, therefore, regulates the blood-supply of some part of the brain, of the ear, of the face, and of the eye — ^be divided, or, better still, if the ganglion from which that branch springs be removed, we see that the entire half of the head of the animal, on the side on which the operation has been performed, be- comes hotter, and, on examining more closely, we dis- cover that the increase of heat is due to the fact that the blood-vessels allow more blood to pass through them, that the nutrition of the parts is increased, and therefore the heat also increases ; and we see that the upper eyelid of the animal drops a little, being in a state of hypersemia — that is, its capillaries are dis- tended — that the secretion of tears is increased, so that the eye is wet, that the pupil of the eye is con- tracted, because of more blood in the ciliary system, etc. " The ear also becomes hotter, and, if the animal is white, we can see that the ear which before was white, with some blood-vessels stretching across, is now be- come red, and presents a rich network of capillaries, which have become apparent, being of enlarged calibre, l^ow, all these phenomena may disappear after a while, except a few. The eye always remains smaller, ah though the blood-supply of the eyelid is more regu- lated ; the pupil remains a httle contracted and the secretion of tears continues, and also the nictitant membrane remains in a congested state. 'No matter how long the animal lives, that state of the eye per- ACQUIRED AND ABNORMAL CHARACTERS. 61 sists, and, when the animal dies, or is sacrificed, it is seen that this eyeball is smaller than its fellow. " If, now, such an animal were allowed to breed with another, whether operated npon in the same manner or not, it would be seen that young which are born apparently perfectly healthy present, a few days after birth, all the phenomena observed in their changed parent or parents. They have the same smaller eyes, but on both sides, the same ear thick- ened and enlarged, etc. " The only phenomena which they do not show are those which have been transient — the increased heat and the increased sensation which depended upon the increased amount of blood present, etc. Those young can be made to breed in-and-in for several genera- tions. I have watched them for five generations, and always the same characteristics will be discovered in the young." " If, now, an examination is made of the parent, the first one, it will be seen that the nerve that had been sectioned, or its ganglion which had been extir- pated, is not regenerated ; while, if an autopsy is made of one of the offspring of any of the subsequent gen- erations, it is seen that they all possess the nerve and the ganglion intact. The acutest or most minute mi- croscopic examinations do not discover any difference between their structure and those of other animals of the same family and species." * In these cases the permanent modifications of the eye and face, resulting from the injury to the nervous system, are entailed upon the offspring, while the * Popular Science Monthly^ July, 1877, pp. 333, 334. 62 PRINCIPLES OF STOCK-BREEDING. nerves that have been mutilated are transmitted in their original integrity. The following cases, given hj Dr. Dupuy, are of particular interest from the series of changes repeated in the offspring that have not apparently inherited the original lesion of the nervous system that produced them: " If a puncture be made into that portion of the upper part of the spinal cord which anatomists call the restiform body, in Guinea-pigs, it will be seen that the animal presents at once an increased vascularity of the ear on the corresponding side ; the ear becomes gorged with blood, chiefly toward the periphery; sometimes, in a very short time, indeed, that portion of the ear falls off, destroyed by dry gangrene. " I have the record of a case in which the ear was thus partially destroyed in less than nine hours. The eye on the same side becomes larger and protrudes ; it protrudes first, and becomes larger in the course of time. If a pair of Guinea-pigs thus operated upon be allowed to breed, and even if only one parent is thus diseased, the other being healthy, when young are born these young always present the phenomena ob- served in the parents; but the phenomena just de- scribed only come shortly after their birth. " It is seen that their eyeballs increase in size and protrude from their sockets; their ears after a few days become diseased, just like those of the parents, the subjects of experimentation, and drop off, eaten by dry gangrene. "When the parent or parents are sacrificed, and their restiform bodies are examined microscopically, ACQUIRED AND ABNORMAL CHARACTERS. 63 notliing is detected but a cicatrix in the envelopes of the spinal cord, which appears a little thickened at that point ; but the nervous tissue itself does not dif- fer apparently from surrounding elements of the same nature and structure. " If an examination is also made of one of the young, nothing at all is discovered. " These young can be allowed to breed in-and-in, and always the same phenomena will be observed in each subsequent generation. " I have sometimes noticed that if a male or a fe- male belonging to any one of the successive genera- tions is allowed to breed with another healthy animal, very generally some of the young present the same hereditary peculiarities. I have followed animals thus operated upon through seven generations." ^ In the experiments of Dr. Brown-Sequard with Guinea-pigs, it was found that an injury of the spinal cord, or of the sciatic nerve, produced a change in sensation over a certain well-defined area of the face, in addition to the epileptic affection already referred to. "When the sciatic nerve was the seat of the injury the outer part of the foot was likewise destroyed, leaving but one toe, the inner, on the foot of the in- jured side, and this deformity is a permanent one. When the animals recover from the epileptic affec- tion, as they do after several months, " all the phe- nomena observed about the zone of skin in the neck and face recur in the reverse order ; that is to say, all the different sensations return by degrees, at the same time that the hair of the region falls, and new hair » Popular Science Monthly, July, 18YY, pp. 334, 335. 64: PRINCIPLES OF STOCK-BREEDING. grows gradually. The fits become simple convulsions, then mere twitchings, and lastly the animal can no longer be distinguished from another healthy one, but by the fact that it has only one toe at one of its hind- legs, when the operation has been performed on the sciatic nerve ; and nothing whatever remains when the origin of the disease was a prick in the spinal cord." ' The young of these epileptic Guinea-pigs are bom apparently healthy, with the exception of those from parents that had been subjected to the injury of the sciatic nerve, and they have but one toe on one of the hind-feet. "When these apparently healthy animals are two or more months old they gradually become affected with epilepsy, and the same area on the face and neck passes through the same series of changes in the development and cure of the affaction that had been observed in their parents. " "We see the gradual increase of the affection, the diminution of the sensi- bility in the zone, just as with the parents, the coming of a period of complete attacks of epilepsy, and then the loss of hair and the gradual diminution of the nervous complaint." ' In the original parents, it will be observed that the derangement of the nervous system, resulting in con- vulsions, was produced by an injury to the spinal cord or the sciatic nerve, and, when these injuries had healed, the nervous symptoms gradually disappeared, the hair is shed from that part of the face affected, and gradually replaced, and the cure is complete. * Popular Science Montlily^ July, 1877, p. 337. " Loc. cit, p. 337. ACQUIRED AND ABNORMAL CHARACTERS. 65 ]N"ow, tlie young of these animals that liad recov- ered from their injuries are born with a nervous sys- tem that is apparently perfect ; and yet, after a time, the disease is developed, passes through its peculiar stages without apparent cause, and finally disappears. The functional derangement of the organization is apparently transmitted without being accompanied by any anatomical lesions that can be assigned as an ex- citing cause. CHAPTEE V. ATAVISM. Ant peculiarity of an ancestor, more or less re- mote, whether of form, color, habits, mental traits, or predisposition to disease, may make its appearance in the offspring without having been observed in the parents. This form of heredity, technically termed atavism (from atavus, an ancestor), is called reversion by Mr. Darwin, and it has for a long time been recognized by breeders, under a variety of names, as " throwing back," " crying back," " breeding back," etc. It will, perhaps, be better to retain the term ata- vism, which has been so generally in use to indicate this class of cases, as it does not involve in its signifi- cation any theoretical explanation of the phenomena. Some of the cases cited in the preceding pages, to illustrate other phases of the great law of heredity, are likewise examples of atavism, and we shall find also in the cases quoted in this connection many illustra- tions of topics discussed in other chapters. Of the multitude of cases on record of this form of heredity, the following will serve to illustrate its leading feat- ures. Mr. Darwin states that the following case was communicated to him on good authority : " A pointer- ATAVISM. 67 bitch produced seven puppies. Four were marked with blue and white, which is so unusual a color with pointers that she was thought to have played false with one of the greyhounds, and the whole litter was condemned ; but the game-keeper was permitted to save one as a curiosity. " Two years afterward a friend of the owner saw the young dog, and declared that he was the image of his old pointer-bitch Sappho, the only blue-and-white pointer of pure descent which he had ever seen. This led to close inquiry, and it was proved that he was the great-great-grandson of Sappho ; so that, according to the common expression, he had only one-sixteenth of her blood in his veins." ^ Mr. Tollett, of Betley Hall, crossed his fowls with Malays, and, though he attempted to get rid of this strain, he gave it up in despair, the Malay characters reappearing forty years after the cross was made.' Mr. Hewett states that the Eumpless fowls in some instances produce young with tail-feathers, but that, when three such birds were selected to breed from, there was but one chick with a tail out of over twenty bred from the trio.' Goodale relates an interesting case that occurred in the Kennebec Yalley. Many years ago there were a few polled cattle in that locality, but they finally became extinct. For thirty-five years after the last of these polled cattle was killed the cattle on the farm of Mr. Wingate all had horns, but, at the end of that 1 "Animals and Plants under Domestication," vol. ii., p. 46. ' On the authority of Mr. Darwin, he. cit., p. 49. 3 Tegetmeier's "Poultry-Book," p. 231. 68 PRINCIPLES OF STOCK-BREEDING. time, a polled animal made its appearance in his herd, with all the characteristics of the original breed. ^ It is stated, on the authority of Mr. Sidney, that in a litter of Essex pigs two yonngones appeared with marks of the Berkshire that had been used as a cross twenty-eight years before.^ The occasional appearance of horns in the Gallo- way, Suffolk, and other polled breeds that have been bred pure for many years, furnishes an illustration of the transmission of an original character by atavic descent. Mr. Sedgwick says, " In the well-known case of George III., the insanity was transmitted in the male line, by atavic descent from a male ancestor, eight generations back, in whom not only the insanity, but many other of the well-known characteristics of the unfortunate monarch, were exactly repeated." ' In the case of a woman with a sixth finger on one hand, related by Dr. Struthers, only one out of eigh- teen children had an extra finger, and, in this case, both hands were affected. One of the sons, James, had two sons and seven daughters, all, like himself, with the normal number of fingers. One of his daughters, however, had a son with six fingers on each hand. Two generations were thus free from the defect, but, when it made its appearance in the next genera- * " Principles of Breeding," p. 65. ' "Animals and Plants under Domestication," vol. ii., p. 49 ; from Youatt on " The Hog," 1860, p. 27. 2 British and Foreign Medico- CMrurgical Review^ April, 1863, p. 467. See also " The Four Georges," by Thackeray, pp. 5, 6, 1861. ATAVISM. e9 tion, the intensity of transmission was increased rather than diminished, as both hands were affected instead of one, as in the case of the great-great-grandmother.^ Dr. Chadbonrne reports a case that came nnder his own observation, of two yonng men who were cousins, " each of whom had six toes npon his feet." ]S'either of the parents had the defect, but it was a characteristic of the grandparents, and appeared in the family a long time before.* Mr. Sedgwick, in his article on the " Influence of Sex in Hereditary Disease," says, " Siebold records the case of a married couple whose fathers were both red-headed, but not having red hair themselves, who had four sons red-headed, and three daughters whose hair was of another color." ' In the Short-horn herd-books may be found numer- ous instances of the atavic inheritance of color, and almost every breeder can furnish from his own expe- rience many cases of a similar character. The follow- ing is cited as an example of this class of cases : " Mr. "Wadsworth owns the twin Princess cows. Lady Mary seventh and eighth ; they are both good roans, got by fourth Lord of Oxford (5903 " American Herd-Book "), a roan bull ; their dam. Lady Mary, a red, got by Hot- spur (31393), a roan ; their granddam. Baroness, a red roan, got by Barrington (30501), a white ; their great- granddam, the imported red Princess cow Ped Rose second, got by E'apier (6238), red roan. These twin heifers. Lady Mary seventh and eighth, were both * Spencer's "Principles of Biology," vol. i., p. 258. » "Agricultural Report of Massachusetts," 1866-'67, p. 88. ^ British and Foreign Medico- Chirurgical Review^ April, 1863, p. 461. 70 PRINCIPLES OP STOCK-BREEDING. served by the Princess bull, Earl of Seabam (8077 "American Herd-Book"), a good roan, and eacb dropped a bull-calf ; but the one from Lady Mary seventh was a red^ while the other, from Lady Mary eighth, was whiteP ^ The late Hon. Charles Rich, of Lapeer, who, when a young man, had charge of the merino sheep that formed the foundation of what is known as the " Rich family of Merinoes," informed me that tan-colored ears was a common characteristic of the Spanish me- rino sheep at that time, and that it was highly prized as an indication of the " blood." Dr. Randall says : " These spots were highly characteristic of several of the families of merinoes originally imported from Spain, and the lambs of some of them were occasion- ally covered over the carcass at birth with larger spots of the same color, or of a deeper tawny-red. Some- times the whole body was thus colored. But all of these tints disappeared on the body when the wool grew out, and were seen no more." ^ These tan-colored spots on the ears and face, and also on the body, are now frequently seen in flocks in which white ears have been the prevailing character- istic for many generations, the original peculiarities of the breed being transmitted by atavism. The "dark noses," so frequently seen in short- horns, are but a repetition of ancestral characteristics by atavic descent. The following case of atavic transmission of an abnormal peculiarity is reported by Mr. Sedgwick, on » " The Country Gentleman," 1876, p. 105. s " The Practical Shepherd," p. 72, note. ATAVISM. 71 the authority of Dr. Cotton : " A gentleman had, with both dentitions, a donble-tooth in place of the left- second incisor in the upper jaw ; he was the only one in the family of nine children who presented this pe- culiarity, which he inherited from his paternal grand- father, whom he so exactly resembled, even in the form of the hands also, as often to have arrested the attention of their acquaintance." ^ The same authority says : " Borelli, quoted by Rougemont, records the case of a well-made man who was three times married, and whose father had been lame; the children of this man by his three wives were all lame." ^ ' The following case of skin-disease {ichthyosis)^ re- ported by Mr. Sedgwick, illustrates a singular feature in the atavic transmission of disease, from the limit of the defect to the male sex, while its transmission ap- pears to be exclusively limited to females : " It first occurred in the grandfather, who is still living, and who has the disease in a very severe form ; it did not appear in him, or it was not, at least, noticed, till he was about seven or eight years old. " This man has had three sons and three daughters. One son died at the age of ^yq years, and one at the age of seven years, both of whom were free from the disease. The other son is living and past middle age, but has shown no tendency to the disease. The three daughters have all lived to grow up and marry, and in them likewise the skin is unaffected. Two only of the thi-ee daughters have had children. The eldest daughter has had four, of whom the first-born, a girl, » Loc. cit.^ April, 1863, p. 454. « Ibid., p. 464. 72 PRINCIPLES OF STOCK-BREEDING. has had no appearance of the disease ; the three other children are boys, of whom the eldest, aged fourteen years, and the youngest, aged nine years, suffer from the disease, while the other son, aged eleven years, is free from it. " The family of the other daughter consists of three children, the eldest of whom, aged six years, is, as in the former case, a girl, and free from the disease, while the two other children, who are boys, aged re- spectively three years and one year, have the skin very decidedly affected. It is to be noted that the disease, in these grandchildren, has in each case appeared within a few months after birth." ^ A tendency to excessive haemorrhage, from even slight injuries, is well known to be hereditary, and this to such an extent that " in some families scarcely a single male arrives at maturity." In his remarks on the heredity of this diseased condition of the system, Mr. Sedgwick says : " In some of these cases it is re- corded that, while the males alone have suffered from the disease, the females alone have been able to trans- mit it, as in the case of Mr. Appleton, whose daugh- ters conveyed the complaint to his grandsons, and who, in their turn, transmitted it through their daugh- ters to their grandsons ; the males in this family, as in many others similarly affected, never inheriting the disease direct from their fathers, but always through females from their grandfathers, as occurred in my case of ichthyosis." ^ * British and Foreign Medico- CJdrurgical Review, 1861, p. 246. 2 Loc. cit, July, 1861, p. 146. In the case of Mr. Appleton, above referred to, references are made to the iVeio England Journal of Medi- ATAVISM. 73 The tendency to an alternation of generations in the inheritance of disease, which has already been noticed, appears to be analogous in character to the alternations determined by the limitation of defects to one sex, while the other sex alone seems capable of transmitting them. In many of the lower animals the alternation of generations is the fixed law of generation. In the aphides (plant-lice), for example, nine or ten generations of individuals are produced in succes- sion before those having sexual organs and capable of producing eggs make their appearance; and this succession of non-sexual generations is uniformly re- peated. The phenomena of atavism has been claimed to be but a reversion of the organization to characters be- longing to an original ancestor or type. This, in many instances, appears to be the case ; but, in the alternations that have been observed in the hereditary transmission of disease, and eyen of normal peculiarities, the theory of reversion is far from satis- factory. In the case of Eumpless fowls, as stated by Mr. Hewett, individuals with tail-feathers are of frequent occurrence, and these, as a rule, produce tailless pro- geny.^ If, in the case of individuals with tails, there is reversion to the original type, in those without tails, dne and Surgery^ vol. ii., pp. 221-225, 1813 ; Edinburgh Medical and Surgical Journal, vol. xxxvi., pp. 317-320, 1831 ; and vol. Ixxvii., pp. 1-10, 1852. * Tegetmeier's "Poultry-Book," p. 231. 74 PRINCIPLES OF STOCK-BREEDING. bred from parents with tails, there must be revefsion again to the tailless form. From the facts, as now understood, it appears that two antagonistic characters are alike inherited, either one of which may become dominant in the offspring. The alternation of the character, in different gen- erations, may thus be produced by the development of the one or the other of two characters belonging as strictly to the organization, through inheritance, as any other part of the system. Although we may not be able, in the following cases, to trace the principle of alternation in atavic descent, they are, nevertheless, of interest in this con- nection, from their close resemblance, in some respects, to the cases under discussion. " A physician at Marseilles relates a case in which deafness from birth occurred in three children alter- nately in a family of six. The parents were not af- fected. . . . M. Saissy refers to a family living at Aix, in Savoy, composed of seven children : the eldest is deaf and dumb, the second hears perfectly, the third is deaf and dumb, and the fourth enjoys the same ad- vantage as the second; the fifth, sixth, and last, are completely deaf — the last but one (the sixth) in this case being an idiot. There was no defect in either parent. ... A similar case occurs in the commune of Bessenay, department of the Khone; in a family composed of eight children four are deaf and dumb, and alternate with four who enjoy the sense of hear- ing." Claude relates the case "of a woman who gave birth to eight children of one and the other sex, the ATAVISM. 75 first, third, fifth, and seventh, of whom attained the ordinary size, while the other four were dwarfs." In a family of eight children, four sons alternating with four daughters, the sons were all healthy, while the daughters were all affected with brain-disease (hydrocephalus), the only one living being an infant under treatment.^ From the persistent appearance of the defects in these cases in regular alternate succession, we must admit the probability, at least, of the existence of some hereditary taint of the system, derived from ancestors whose history we are unable to trace. In the chapter on " Sex " may be found cases in which the defect is limited to one sex ; and this, in families of both sexes, would result in an alternation more or less regular in its inheritance. In a large family we seldom find all of the chil- dren resembling either the father or the mother, and, in many instances, the resemblance to a grandparent or some more remote ancestor prevails to so great an extent that the obvious peculiarities of the immediate parents are obscured. Prof. Agassiz'^ has remarked that " the offspring is not the offspring of father and mother, but of grandparents as well," and he might also have included all of the ancestors in the parental enumeration. The alternations observed in the transmission of ancestral characters, and the resemblance of offspring ^ The last five cases are quoted from Mr. Sedgwick's paper on the " Sexual Limitation of Hereditary Disease," in the British and Foreign Medico- Chirurgical Review^ July, 1861, pp. 141, 142, 146. ^ "Agricultural Report of Massachusetts," 1866-'67, p. 82. 76 PRINCIPLES OF STOCK-BREEDING. to a remote ancestor, that differs in many respects from the parents, cannot be referred to a " spon- taneous variation " in the law of inheritance, for we cannot conceive of an ejffect without an efficient cause. The repetition of some preexisting character is so uniformly observed in all cases of apparent variation in the transmission of qualities, in which the history of the ancestors can be traced, that we cannot avoid the conclusion that these pecuKarities in the heredity of the organization are the result of some constant and definite physiological law. If the form in which the physiological units or elements of the organization were transmitted could be determined, the obscurity involved in this class of cases would in great measure disappear. In discussing the subject of inherited resemblance, Dr. Carpenter remarks that "the question seems to have been entirely ignored, whether the union of two different natures may not produce — as in the combi- nation of an acid and a base — a resultant essentially dissimilar to either of them." ^ If two characters may thus blend to form a new character essentially different, there could be no con- stancy in the transmission of ancestral forms from generation to generation, and a wide variation from the family type would necessarily result. There could be no uniformity in the leading characteristics of our improved breeds, and, with our present kaowledge of physiological science, the breeding of animals would be attended with the greatest uncertainty, from our » " Mental Physiology," p. 369. ATAVISM. Y7 inability to predict what a given combination would produce. Moreover, the phenomena of atavism cannot be reconciled with this hypothesis, without the further supposition that the elements of the organization, combining to form a new compound, may be again resolved into their original constituents. When characters that have remained latent for several generations make their appearance again, with all the peculiarities that formerly distinguished them, it does not seem probable that they have passed through a series of transformations in the formation of new characters, and, at the same time, retained their original constitution. From the facts of heredity already presented in the cases cited, it must be evident that the sum of the characters or physiological units that enter into the organization of the animal cannot be represented in the external peculiarities that alone are obvious to the senses. It is well known to breeders that many of the most important characteristics of the organization, in a given case, may not appear upon the surface, or in the functional activities of the system, and that they can only be traced in the ancestral history, and in the inherited peculiarities of offspring. In the further discussion of these peculiar forms of heredity, it will be necessary to distinguish between the more obvious and prominent characters of the ani- mal and those obscure characters that can only be shown to exist by their hereditary transmission to off- spring. The former may be termed dominant char- acters, and the latter obscured or latent characters. 78 PRINCIPLES OF STOCK-BREEDING. For many years I have been inclined to the belief that all characters are directly transmitted as physio- logical nnits or elements of the organization, some of which may be dominant, and thns determine the ob- vious characteristics of the animal, while others re- main latent until they are transmitted to offspring in which favorable conditions lead to their development, when they, in their turn, may become dominant, and thus obscure other characters. That characters are transmitted in their integrity, without transformation into other characters, is clearly asserted by Herbert Spencer, who says, " There must arise not an homogeneous mean between two parents, but a mixture of organs, some of which mainly follow the one parent, and some the other." ^ The last clause of this statement cannot, however, be literally accepted as a law of inheritance, as we have already seen that the dominant characters, in a given case, may be inherited from some remote ances- tor, while the dominant characters of the parents may become latent. Mr. Sedgwick, in his paper on " Hereditary Dis- ease," says : " It may be observed that in the offspring of two dissimilar parents there is never, as a rule, complete fusion of the two parents, but a distribution of the characters peculiar to each ; and although this is less strongly remarked in the offspring of the human race than it is in that of the lower animals — as, for ex- ample, in the case of some hermaphrodite insects, in which the family quarterings may result from specific distinctions of sex being associated without fusion in ^ " Principles of Biology," vol. i., p. 267. ATAVISM. 79 the same specimen, yet, as regards the inheritance of disease, it will be f onnd that the morbid characteristics of one or the other parent are either completely re- peated or completely absent, bnt not fused together in the offspring. This is what is meant in inheritance by the doctrine of 'election,' which is based on the observation that certain attributes of organization pe- culiar to one parent are repeated in the offspring ; and it offers a reasonable explanation of the fact that chil- dren often inherit the defects of one parent, while in many other respects they resemble the other ; and the inheritance in these cases, both natural and morbid, may sometimes be conveyed to them by atavic de- scent." ^ If it is admitted that the animal inherits an assem- blage of peculiarities representing the aggregate of parental characters, it must follow that all of the char- acters of all ancestors are in like manner inherited, as each generation would inherit and transmit the pecu- liarities of the preceding generation, and this, in turn, would inherit and transmit the peculiarities of the next preceding, and so on indefinitely. The phenom- ena of atavism seem to show that we cannot set a limit to the inheritance of characters. Theoretically, a defect or peculiarity may be "bred out," as it is ^ British and Foreign 3fedico-Chirurgieal Review^ J^^y? 1863, pp. 190, 191. As an illustration of the distinct inheritance of qualities, the case is given of " the scarce egger-moth, observed by Mr. West- wood" ("Entomologist's Text-Book," p. 397, 1838), "at Berlin, in which the front-part of the body and front-half of the wings were half male and half female, and the hind-part and hind-wings half fe- male and half male, the characters of the male and female insect being exhibited on opposite quarters of this specimen." 80 PRINCIPLES OF STOCK-BREEDING. termed, until it is represented mathematicallj by a fraction so small as to scarcely merit attention, and yet, as frequently observed, it may again appear in a manner indicating that it lias been constantly trans- mitted, without change, through a long series of gen- erations. Mr. Sedgwick remarks, in regard to atavism in disease, that "no fixed boundaries, recognizable by us, can be expected to limit its operation, for, like other general laws in l^ature, unity in principle coex- ists with variety in results ; and it is chiefly because we are less familiar with the results of atavism in dis- ease than we are with many other reproductive phe- nomena, as, for the sake of illustration, with memory, that we hesitate to accept them, although they are not, in themselves, more exceptional or peculiar than some of those are which we not only never hesitate to accept, but with which this phenomenon in morbid development seems to be closely allied. For atavism in disease appears to be but an instance of memory in reproduction, as imitation is expressed in direct de- scent ; and in the same way that memory never, as it were, dies out, but in some state always exists, so the previous existence of some peculiarity in organization may likewise be regarded as never absolutely lost in succeeding generations, except by extinction of race." * It has been remarked that no two animals are pre- cisely alike, in all details of the organization, no mat- ter how close the relationship or how striking the re- semblance ; and, in connection with this, it has been observed that instances occur in which individuals ^ British and Foreign Medico- Chirurgical Review ^ July, 1863, p. 197. ATAVISM. 81 present an assemblage of characters quite different from those that characterize the parents. These have been explained on the supposition that there mnst be a law of " spontaneity " which is antagonistic to that of heredity, or that the law of heredity is not constant in its action, but limited by numerous exceptions/ The view we have presented of the law of inheri- tance would seem to preclude the necessity of any such hypothesis to account for the individual varia- tions referred to. Many of the cases of supposed variation are fully explained on the principle of atavic descent, which is, as we have seen, but a phase of the great law of heredity. If characters are transmitted as physiological units, it will be readily seen that, although an animal may be composed of precisely the same elements as its an- cestors, the dominance of some of these, or the ar- rangement of the elements themselves, must give rise to individual peculiarities, or even to forms not pre- cisely identical with those exhibited in the dominant characters of any ancestor. Any observed variations in the inheritance of form, color, or general character- istics, may thus be readily accounted for, within the limits of the characters belonging to the ancestors. In these cases of apparent variation, the similarity of the offspring to its ancestors consists in the posses- sion of the same assemblage of characters which is often shown in a general rather than a special resem- blance. From the complexity of the elements trans- mitted from generation to generation, we cannot ex- pect the offspring, in a particular case, to be the exact 1 Ribot on " Heredity," p. 194, etc. 82 PRINCIPLES OP STOCK-BREEDING. connterpart, in dominant characters, of either parent or of any ancestor ; but, on the other hand, we have no reason to believe that any characters will appear that have not been derived by direct or interrupted descent from some ancestor. "When speaking of the resemblance of offspring to ancestors, in a popular sense, the dominant characters are- alone referred to ; but, as these, as has been shown, may constitute but a small proportion of the elements of the organization, a strict comparison of resemblances must include a wider range of characteristics. In this connection, the importance of a full record of the pedigrees of breeding animals will be readily suggested, as a means of tracing the history of ances- tors, for the purpose of determining the characters that are liable to be transmitted by atavic descent. As the subject of pedigree, however, involves a num- ber of questions that have not as yet been examined, a full consideration of its practical bearings must be, for the present, omitted. CHAPTER YI. LAW OF COREELATION. The external form and general characteristics of an individual, as determined by heredity, are the re- sult, as we have seen, of the prominence of those characters that are made dominant, and the suppres- sion of others which, for the time being, are said to be latent. In the arrangement of these dominant characters in the organization, a principle of develop- ment and suppression appears to prevail, which is recognized by naturalists as the law of correlation. This law may be defined in general terms as follows : Any peculiarity in the development of one organ, or set of organs, is usually accompanied by a correspond- ing modification or suppression of organs belonging to some other part of the system. In this place we shall only notice the relations of this law to heredity, reserving for another chapter its applications in deter- mining internal qualities from peculiarities of external conformation. The correlated structure of animals enables the comparative anatomist, from the examination of a single tooth, or fragment of bone, to determine not only the class and order to which an animal belongs, but its habits and mode of life, and the character of 84: PRINCIPLES OF STOCK-BREEDING. the food required for its support. The celebrated naturalist, Milne-Edwards, in his article on Crustacea, says, " It has long been admitted as an axiom in ani- mal physics that, when any particular part of the body acquires a very high degree of development, certain other parts stop short of their ordinary state of evolu- tion, as if the former had obtained their unusual incre- ment at the cost of the latter." ^ Cuvier, the great comparative anatomist, claimed that "all organized beings, in their structure, form a complete system, of which the parts mutually cor- respond and conduce to the same definite action by a reciprocal reaction. Each of these parts cannot be changed without the others changing also; and, by consequence, each of these taken separately indicates and gives all the rest." " Prof. Owen, in his valuable work on the " Com- parative Anatomy of the Vertebrates," gives the fol- lowing illustrations of this law of development : " As vertebrates rise in the scale, and the adaptive principle predominates, the law of correlation, as enunciated by Cuvier, becomes more operative. In the jaws of the lion, e. g., there are large laniaries, or canines, formed to pierce, lacerate, and retain its prey. . . . There are also compressed, trenchant, flesh-cutting teeth, which play upon each other like scissor-blades in the move- ment of the lower upon the upper jaw. The lower jaw is short and strong ; it articulates to the skull by a transversely-extended convexity, or condyle, received 1 " Cyclopaedia of Anatomy and Physiology," vol. i., p. TSY. ^ As quoted by Prof. Owen, " Comparative Anatomy of the Verte- brates," vol. i., p. 27. LAW OF CORRELATION. 85 into a corresponding concavity, forming a closelj-fit- tiQg joint, which gives a firm attachment to the jaw, but almost restricts it to the movements of opening and closing the mouth. The jaw of the carnivora de- velops a plate of bone, of breadth and height adequate for the implantation of muscles, with power to inflict a deadly bite. " These muscles require a large extent of surface for their origin from the cranium, with concomitant strength and curvature of the zygomatic arch, and are associated with a strong occipital crest and lofty dorsal spines, for vigorous uplifting and retraction of the head when the prey has been griped. " The limbs are armed with short claws, and en- dued with the requisite power, extent, and freedom of motion, for the wielding of these weapons. These and other structures of the highly-organized carnivora are so coordinated as to justify Cuvier in asserting that * the form of the tooth gives that of the condyle, of the blade-bone, and of the claws, just as the equation of a curve evolves all its properties, and exactly as, in taking each property by itself as the base of a particu- lar equation, one discovers both the ordinary equation and all its properties, so the claw, the blade-bone, the condyle, the femur, and all the other bones individu- ally, give the teeth, or are given thereby reciprocally, and, in commencing by any of these, whoever pos- sesses rationally the laws of the organic economy will be able to reconstruct the entire animal.' " " The law of correlation receives as striking illus- trations from the structure of the herbivorous mam- mals." A limb terminating in a hoof serves for loco- 86 PRINCIPLES OF STOCK-BREEDING. motion only ; it cannot be nsed as an organ of prehen- sion, to grasp, seize, or tear. The ruminant hoofed animals all have a cloven hoof, and they are the only ones with horns on the frontal bone. When the hoofs are in one or two pairs, the horns are also in one or two pairs. The horned ungulates, with three hoofs, have either one horn, or two horns placed one before the other, in the middle of the skull. ^ In the ruminants there is, moreover, a marked cor- relation in the form of the teeth, the articulation of the jaw, which provides for a free lateral motion in grinding their food, and the complex structure of the digestive organs. Dr. Carpenter says : " It is perfectly true that, in a great majority of cases, the extraordinary develop- ment of one organ is acGomjpanied by a corresponding deficiency of development in another. Thus, in the human cranium, the elements which form the cover- ing or protection of the brain are very largely devel- oped, while those which constitute the face are com- paratively small. In the long-snouted herbivorous mammals, and in reptiles and fishes, on the other hand, the great development of the bones of the face is coincident with* a very small capacity of the cerebral cavity. " In the bat, while the anterior extremity is widely extended, so as to afford the animal the means of rising in the air, the posterior is very much lightened, so as not to impede its flight. In the kangaroo, on the other hand, the posterior members are very large and ^ Owen's " Comparatiye Anatomy of the Vertebrates," vol. i., pp. xxvii., xxviii. LAW OF CORRELATION. 87 powerful, enabling tlie animal to take long leaps, while the fore-paws are proportionally small." ^ In blind persons the sense of touch attains a deli- cacy that is surprising. " It is well known that Dr. Saunderson, the cele- brated blind Professor of Mathematics at Cambridge, not only acquired a very accurate knowledge of med- als, but could even distinguish genuine medals from imitations, more certainly than most connoisseurs in full possession of their senses." ' Cases are on record of blind persons who could not only distinguish colors, but shades of the same color. The muscular sense which is employed by the blind, in connection with touch, in discriminating the form, peculiarities of surface, and size of objects, becomes in these cases remarkably developed.^ It is stated that persons affected with color-blind- ness frequently have a defective musical ear.* The sense of smell, in some blind persons, is so ex- ceedingly acute that they are enabled, by it alone, to recognize persons not in immediate contact with them. " In the well-known case of James Mitchell, who was deaf, blind, and dumb, from his birth, it was the principal means by which he distinguished persons, and enabled him at once to perceive the entrance of a stranger." ^ * " Comparative Physiology," p. 130. 2 "Cyclopaedia of Anatomy and Physiology," vol. iv., p. 11 78. 3 Ibid., loc. cit. * See Dr. Earle's article in the American Journal of the Medical, Sciences, vol. xxxv., p. 34*7 ; and article " Vision," " Cyclopaedia of Anat- omy and Physiology," vol. iv., p. 1453. ^ " Cyclopaedia of Anatomy and Physiology," vol. iv,, p. 102. 88 PRINCIPLES OF STOCK-BREEDING. Mr. Darwin states that " black dogs, with tan-col- ored feet, whatever breed they may belong to, almost invariably have a tan-colored spot on the upper and inner corners of each eye, and their lips are generally thus colored." ' According to the same author, " white cats, if they have bine eyes, are almost always deaf." In the cases cited it is shown that, if there is the " least speck of color on their fnr," or if even but one eye is not blue, the sense of hearing is not lost ; and, in one instance, in which the iris at the end of four months began to grow " dark-colored," the cat then began to hear.' It has been remarked that a white spot or blaze on the face of a horse is usually accompanied by white feet. In the deer tribe. Prof. Baird notices a singular correlation of the horns and organs of reproduction. He says : " In all deer, except, perhaps, the reindeer, if the male be castrated when the horns are in a state of perfection, these will never be shed ; if the opera- tion be performed when the head is bare, they wiU never be reproduced ; and, if done when the secretion is going on, a stunted, ill-formed, permanent horn is the result." ' Mr. Youatt remarks that a " multiplicity of horns is not found in any breed (of sheep) intrinsically of much value. It is generally accompanied by great length and coarseness of fleece, and which, in the ma- * " Animals and Plants under Domestication," vol. i., p. 42. ' Zoc. cit.y vol. ii., p. 396. 3 "Patent-Office Report," Part II., "Agriculture," 1851, p. 111. LAW OF CORRELATION. 89 jority of these cases, assumes more the form of hair than of wool." * The tusks, which attain a great size in the boar, are not fully developed in swine that are castrated.' What are called the secondary sexual characters of the male are not developed in animals that are cas- trated ; and, among birds, it has been observed that females incapable of breeding, from age or the effects of disease, sometimes assume the plumage and voice of the male." The cock of the Sebright bantams should be hen- tailed and without sickle-feathers, thus presenting a close resemblance to the female. This character, so highly prized by exhibitors, has, however, its disad- vantages. Mr. Hewitt remarks, in regard to these breeds; " The combined experience of many other admirers of the Sebright bantams is concurrent with my own, viz., that even a very trifling disposition to sickle- feather in the tail brings with it proportionably in- creased productiveness ; and that, on the other hand, absolute perfection of hen-tailed character in the male bird as generally entails sterility." * The tail is entirely wanting in Rumpless fowls, and it is said that they " are sadly prone to lay unfer- tilized eggs." * The law of correlation, in its relations to structure ' " Sheep," p. 141. ® Journal of the Royal Agricultural Society^ vol. xv., p. 285. 3 "Animals and Plants under Domestication," vol. ii., p. 68. ^ Tegetmeier on " Poultry," p. 245. 3 Ibid., p. 232. ^ 90 PRINCIPLES OF STOCK-BREEDING. and function, furnishes tlie best explanation of the difficulty experienced by breeders in retaining and developing, in their greatest perfection, two essential- ly different functions in the dominant characteristics of the same animal. In attempting to secure the highest development of some particular quality, a gradual and, it may be, an undesirable change is so often observed in the qualities depending on the functional activity of some other part or parts of the system as to lead to the be- lief that the quality that is retained is incompatible with a high development of the function that is im- paired in its activity. A deficiency in the production of milk has often been noticed in animals that are remarkable in the tendency to fatten. Mr. Price, a noted breeder of Hereford cattle, says : " Experience has taught me that no animals possessing form, and other requisites giving them a great disposition to fatten, are calcu- lated to give much milk; nor is it reasonable to sup- pose they should — ^it would be in direct opposition to the law of JSTature. Had I willed it twenty years ago, my belief is that I could, by this time, have bred twenty cows, purely from my own herd, which should have given a sufficient quantity of milk for (paying) dairy purposes ; and I am equally confident that, in the same period, I could have bred a similar number that would not, at any time, have given twenty quarts of milk per day among them. "I feel confident I could effect either of these objects much more easily and certainly than I could blend the two properties in the same animal, retain- LAW OP CORRELATION. 91 ing also tlie form and quality best adapted to live hard and feed." ^ It is not claimed that higli feeding qualities cannot be combined with good milking properties, but that it is easier to excel in either single quality than to se- cure a high development of both. It does not, as a matter of course, follow that antagonistic characters are strictly incompatible. Additional illustrations of the law of correlation may be found in the chapters relating to other topics ; the facts abeady cited will, however, serve my present purpose, as they clearly indicate that an intimate relation exists between the characters that are comprised in the dominant features of the organization, and that these characters are trans- mitted in their integrity, without essential change. An equilibrium of the organization can only be obtained by an arrangement of its elements in strict accordance with the law of correlation. Any modifi- cation of even a single character may, therefore, in- volve corresponding changes in other parts of the sys- tem, and a consequent rearrangement of the dominant characteristics. When the balance of the system is in this manner disturbed, it is difficult to determine the extent of the change that may follow, as it may result in trans- posing the latent and dominant characters, and develop in the offspring a resemblance to some remote ances- tor. ^ i^armer's Magazine, vol. xiv., p. 50. See also CuUey on " Live- stock," fourth edition, 1807, p. 87. CHAPTER YII. VAEIATION. OuE domestic animals, in common with other spe- cies, are endowed with a flexibility or plasticity of the organization that enables them to adapt themselves to the conditions in which they are placed. As a result of a favorable change in the conditions to which ani- mals are subjected, important modifications of the system are obtained, that we recognize as improve- ments in form and qnahty; while deterioration and loss of valuable characters follow when the prevailing conditions of life are unfavorable to the full and healthy development of the organization. From the fact that variations are more readily pro- duced in domesticated varieties than in wild species, it would appear that the change of conditions involved in the process of domestication has not only produced a wide range of variations in the characteristics of animals, but developed an increased plasticity of the organization that renders them more susceptible to the influence of modifying causes. The distinguishing characteristics of the various breeds of animals have been produced, in the main, by the modifying influences that prevail in the locali- ties in which they have originated. VARIATION. 93 In tlie improved families of pure-bred animals, tlie influence of artificial conditions in modifying charac- ters is further shown in the excessive development obtained in special directions. The principal causes of animal variation are cli- mate, food, and habit ; the influence of the first two, in many cases, being so intimately connected that it is difficult to determine what is due to each, while all of them may at times act together. Of the many illus- trations of the modifying influence of climate that might be drawn from the vegetable kingdom, we shall only present some general statements in regard to two of our leading crops. Indian-corn (maize) has a wide geographical range, but in its distribution and development it is influenced in a great degree by climatic conditions. In North America its extreme limits at the IN^orth " are defined by the isothermal of 67° for July, and it may go be- yond 65° for the summer ; one month, however, being required at a higher mean than this." ^ In E'orthem Europe, including Great Britain, the comparatively low summer temperature prevents the ripening of this valuable cereal, although it is grown in some localities as a forage-crop. The time required for ripening the crop in locali- ties where it is grown varies -greatly with the climate. In its extreme northern range, where the smaller va- rieties only are grown, but from two to two and a half months are required to bring it to maturity, while at the South a period of from ^yg to six months is neces- sary. * Blodgett's " Climatology of the United States," p. 420. 94 PRINCIPLES OF STOCK-BREEDING. Heller, in describing the variations in maize culti- vated in Mexico, states that the time of ripening varies from " seven months to six weeks." ^ At the ]^orth the plant presents a dwarfed ap- pearance, while at the South the stalks are very large, the ears frequently being higher than a man can reach. A collection of corn that I made in 1876, to illus- trate the variations produced by climate, represents many interesting features in the character and distri- bution of varieties. At the IN'orth the cob, as a rule, is larger in pro- portion than in the Southern varieties, or in apparent- ly the same varieties grown in the Middle States. At the ISTorth the flint varieties are exclusively grown, while at the South they are entirely replaced by the dent varieties. The smallest well-developed ear in the collection weighs but half an ounce, while the largest ear turns the scale at one pound eight and a half ounces. The influence of climate upon the distribution and development of wheat is hardly less marked. Samples in my cabinet from British Columbia, Oregon, Canada, Michigan, Hussia, l^orway, Sweden, and Australia, present marked contrasts in their general appear- ance. In ISTorth America a mean temperature of from 57° to 65°, and in England of 60°, for the months of July and August, is required for its full develop- ment. In 1853 the mean temperature of these months in » " Patent-Office Report," "Agriculture," 1847, p. 412. VARIATION. 95 England was from 57° to 59°, which had the effect to diminish the crop from one-half to one-third/ Even peculiarities resulting from a slight differ- ence in locality may have an important influence on the time required for its growth and ripening. Mar- shall states that, in the Cotswold Hills, a " stone might be flung from the country which sows its wheat in August into that which sows its wheat in Decem- ber." =« A variety of food is required by animals, so that each organ concerned in the process of nutrition may perform its fair proportion of work, and thus secure a healthy development, resulting in a symmetrical bal- ance of the system. Among animals we cannot fail to observe that the small breeds of sheep and cattle in mountainous regions present a decided contrast to the breeds ob- taining an abundant supply of food in the fertile val- leys of the same country.^ As the relation of the size of animals to the sup- ply of food they are provided with has been noticed by almost every writer on the management of live- stock, we need not, for the present, give a detailed discussion of the subject.* * Blodgett's " Climatology of the United States," p. 446. See also Journal of the Royal Agricultural Society, 1873, p. 379. « " Rural Economy of Gloucestershire," 1789, vol. ii., p. 52. 2 Low's " Domestic Animals," pp. 41, 264. *" Agricultural Report of Staffordshire," p. 174; "Agricultural Report of Middlesex," p. 406 ; Youatt on " Cattle," p. 525 ; Youatt on "The Horse," p. 60; Coventry on "Agriculture," p. 182; Dickson's "Practical Agriculture," vol. ii., pp. 638-640; Cline on "Breeding and Form," p. 12. 96 PRINCIPLES OF STOCK-BREEDING. The great development in fattening quality and in early maturity, that characterizes the modern meat- producing breeds of cattle and sheep, has been secured by a liberal supply of nutritious food during the pe- riod of growth, in connection with a judicious system of breeding, that has fixed and made dominant the desirable modifications thus obtained. The Spanish merino sheep, imported into this country in the early part of the present century, were valued principally for their wool, the peculiar system of management to which they had been subjected for many generations having made them decidedly defi- cient in ability to fatten and in the quality of their flesh. Their descendants, from the influence of modified habits and a better supply of food, present such a wide departure from the original type, in the greater weight and quality of fleece, in the increased tendency to fatten, and the marked improvement in the quality of flesh, that they are jnstly entitled to the distinctive appellation of American merinoes which is now gen- erally given them. The breeders of merino sheep have been directing their attention almost exclusively to the improvement of the fleece, and the greater value of the improved breed for the purposes of the feeder and the butcher has been obtained through the means adopted for the development of other characters. It is perhaps impossible to obtain any decided modification of a single character without producing corresponding modifications of other parts of the or- ganization. TARIATION. 97 In the improvement of the mutton-breeds of sheep, breeders have almost uniformly aimed to secure great- er symmetry in their general proportions, in connec- tion with early maturity, and to diminish any ten- dency to coarseness that may have existed in the ori- ginal breed. In all of the improved breeds of sheep a general refinement of the system has been developed, as the result of the improvements that have been made in special characters, and this has apparently produced a finer fibre of wool, notwithstanding the lack of atten- tion to this particular quality on the part of breeders. In 1835 Mr. Youatt, assisted by Mr. Powell, a manufacturer of microscopes in London, made meas- urements of the wool-fibres of different breeds, which were published in 1840, in his work on " Sheep," ^ as follows : No . of Fibres to the Incli. Saxon .... 840 Merino . . . . 750 (from Lord Western's flock) Odessa wool . 750 Negretti . . " . 750 Common merino 750 Australian wool . 750 New South Wales wool . 750 McArthur's Australian wool I, 780 (Saxon?) Leicester 600 " (from Ireland) . 560 Cheviot .... 500 South-Down 660 The finest sample measured was from the Deccan » Youatt on " Sheep," p. 87. 98 PRINCIPLES OF STOCK-BREEDING. black sheep of India, wliich gave 1,000 fibres to the inch. In 18 64-' 6 5 I measured wool from several flocks, with the following result. With the exception of the Saxon, of which the date of shearing was not known, the samples were all from fleeces of 1864. No of Fibres to the Inch. Saxon ram . . 1242 (from flock of W. H. Ladd, Ohio). u ewe , 1347 a a a (( a (( Silesian ram . . 1352 (( . (( w. Chamberlain, New York. Merino ram (Silver- mine) 1212 u u E. Hammond, Yt. (( " (Sweepstakes) 1186 (( (( u u " (Gold-drop) 1185 (( u (( u ewe (Old Queen) 1275 u u (( (( *' (Queen, 2d) 1183 (( u (( (( " (Queen, 3d) 1138 u u (( a " (Queen, 4th) 1223 (t a u n " (Queen, 5th) 1274 u (( (( t( ram . , 1164 (( (( Hon Chas. Rich, Lapeer, Michigan. Merino ewe 1064 il (( (( (( u u u 1164 u u u (( u 11 (( 1023 a u u (( (( (( u 1022 « il C( (( (( Grade merino ewe 1077 (( u Mich. Agricul. Col. (( (( (( 1249 (( u (( (( (t u « u 1248 u (( u U (( South-Down ewe . 732 (( a (( (( (( u u u 708 u u (( U (( (( n u 742 (( u u u u (( U (( 845 (( (( a U <( In 1877 I measured samples of wool obtained at VAEIATION. 99 the Centennial Exposition at Philadelpliia, in 1876, as follows : No. of Fibres to the Inch. Cheviot ewe, 842 from Ed. Henty, Portland, Victoria, Anst " lamb (( a Leicester . u Lincoln . 579 827 Y32 685 682 769 731 734 Grade Lincoln 874 Merino 790 . 1199 . 1230 . 1173 . 1500 . 1376 . 1079 . 1266 . 1325 . 1180 . 1334 . 1184 . 1208 "Wm. Murray, Brie-Brie, (( a (( u Wm. H. BuUivant, Ovidio Zubianrre, Buenos Ay res, Ar- gentine Eepublic. Ovidio Zubiaurre, Buenos Ayres, Ar- gentine Eepublic. M. Morgan, Argentine Eepublic. E. Goldsbroughj Melbourne, Victoria, Australia. E. Goldsbrougb, Melbourne, Victoria, Australia. Tbos. CummingSj Victoria, Australia. William Lewis, " " U U (( u Eoss and Jas. Eanden " " "William Lang, Wargam, New South Wales, Australia. Buenos Ayres, Argentine Eepublic. Wilfren Latham, Los Alamos, Argen- tine Eepublic. Wilfren Latham, Los Alamos, Argen- tine Eepublic. Mariano Fnsue, Buenos Ayres, Ar- gentine Eepublic. Geronimo Iraizos, Loberia, Argentine Eepublic. 100 PRINCIPLES OP STOCK-BREEDINa. Merino . . 1450 Negretti . . 1138 (( 1081 u 1162 (( 1266 Eambouillet, 1035 u 1062 (( 1150 No. of Fibres to the Inch. 1450 from J. W, Corrales, Buenos Ayres, Argen- tine Republic. George Stegman, Buenos Ayres, Ar- gentine Republic. Charles J. Guerrero, Buenos Ayres, Argentine Republic. Francisco Ohas, Buenos Ayres, Ar- gentine Republic. Samuel B. Hale, Buenos Ayres, Ar- gentine Republic. M. Morgan, Buenos Ayres,- Argentine Republic. Emilio Duportal, Buenos Ayres, Ar- gentine Republic. Emilio Duportal, Buenos Ayres, Ar- gentine Republic. As tliese samples, from widely different localities, are, without exception, miicli finer than the specimens measured by Mr. Youatt, we may safely attribute the change to the same causes that have produced the modifications of form and feeding qualities that char- acterize all of the improved breeds. The Kerry cattle of Ireland are a small and hardy race. The scanty supply of coarse food obtained on their native hills, by industrious efforts, gives a slow growth and a late development of the organization, so that the heifers, it is said, do not breed until six or seven years old. Animals of this breed raised in Massachusetts, un- der more favorable conditions for development, are larger than the original type, and mature earlier, the heifers breeding at the age of three years. VARIATIOIT. 101 As the climate of Massachusetts is not so mild and uniform as that of Ireland, we must attribute the changes observed in these cattle to the influence of shelter during the winter, in connection with a better supply of food. It is a well-known law of the organization that the highest development of any particular organ, or set of organs, can only be attained by their repeated and systematic exercise. The athlete, as well as the horse in training for a race, must perform an amount of work that taxes the system severely, to secure that strength and develop- ment of the muscular system that fit him for the best exhibition of his powers. The highest mental development can only be obtained by severe intellect- ual effort. Mr. Darwin has shown that the proportional weight of the wing-bones of wild-ducks is greater than in tame varieties, while the proportional weight of the leg- bones is greatest in the latter.^ The activity of the glandular system depends largely upon the demands made upon it, in accordance with the same principle. Dr. Carpenter, in his article on the " Yarieties of Mankind," says.: "Another remarkable fact, relative to the oxen of South America, is recorded by M. Eoulin. In Colombia the practice of milking cows was laid aside, owing to the great extent of the farms and other circumstances. In a few generations the natural structure of the parts and the natural state of the function have been restored, the secretion of milk ^ "Animals and Plants under Domestication," vol. i., p. 345. 102 PEINCIPLES OF STOCK-BREEDING. taking place only so long as the caK remains with the mother, and ceasing if it dies or is removed. Hence we have a valuable confirmation of the be- lief previously entertained, that the continued pro- duction of milk by the European breeds of cows is a modified function in the animal economy, origi- nating in an artificial habit kept up through many generations, and dependent upon a modification of structure which that habit has been the means of in- ducing." ^ The practice, too generally prevailing, of raising young animals by means of nurses, so that the mothers may go " dry " and be fitted for exhibition, must re- sult, in a few generations, in a serious deficiency of the milking qualities. Sir Charles Lyell informs us that " some English- men engaged in conducting the mining operations of the Real del Monte Company, in Mexico, carried out l^ith them some greyhounds of the best breed, to hunt the hares which abound in that country. The great platform which is the scene of sport is at an eleva- tion of about nine thousand feet above the level of the sea, and the mercury in the barometer stands ha- bitually at the height of about nineteen inches. It was found that the greyhounds could not support the fatigues of a long chase in this attenuated atmos- phere, and before they could come up with their prey they lay down gasping for breath ; but these same ani- mals have produced whelps which have grown up and are not in the least degree incommoded by the want of density in the air, but run down the hares with as * " Cyclopaedia of Anatomy and Physiology," vol. iv., p. 1312. VARIATION. 103 miicli ease as the fleetest of their race in this conn- try."- In the modifications of form, habits, instincts, and general activity of the functions of organs, resulting from the agencies under consideration, the principle of correlation, to which we have already referred, may be readily traced. "We cannot, in fact, make a decided change in any part of the system without producing a corresponding modification of some other part that is correlated with it. The tendency to early maturity, which is so highly developed in the meat-producing breeds, is accom- panied with a change in the period of dentition, and this fact has to be taken into account in determining the age of animals by the teeth.' There is not only a difficulty in producing a con- siderable modification of several characters at the same time, but there is also the danger of suppressing some character we wish to retain, by the development of a new one not in harmony with it. Family characteristics are produced by limiting the range of variations to the particular standard the breeder wishes to establish. The greatest skill will be required in establishing the family type, to retain, in connection with the desired characters, the qual- ities that give vigor to the constitution and insure an active performance of the function of reproduc- tion, and to prevent, at the same time, the develop- * Quoted from " Cycloptedia of Anatomy and Physiology," vol. iv., p. 1303. * Journal of the Royal Agricultural Society^ vol. xv., p. 328. 104 PRINCIPLES or STOCK-BREEDING. ment of peculiarities that are in themselves objection- able. Erom the manner in which family characters are produced, it will be exceedingly difficult to ingraft any new character upon a family without destroying, to a greater or less extent, its specific characteristics. In the improved breeds, and especially in those in which early maturity and the tendency to lay on fat are highly developed by artificial treatment, the great predominance of one group of characters seems to in- volve an unstable condition of the organization, and a consequent tendency to further variation. It is often remarked that it is more difficult to re- tain a given character than to produce it. If the con- ditions that gave rise to a particular character are changed, the character itself must be changed also. It is a common mistake of those not familiar with the principles of breeding and the causes of variation, to suppose that the highly-artificial characters of im- proved breeds can be retained in the absence of the conditions that produced them. If high feeding has developed a variation in a par- ticular direction, a scanty supply of food would cer- tainly destroy it, and produce a variation of an oppo- site character. Improved characters can only be made permanent by breeding together the animals that pos- sess them, and continuing without variation the same system of management that originally produced them. Improvements that have been effected by better care and an abundant supply of food for many genera- tions, may be lost in a comparatively short time, by placing the animals under less favorable conditions VARIATION. 105 and diminishing their supply of food. A single illus- tration of the effects of neglect will be given : " During the French Eeyolntionary War the ex- cessive price of corn attracted the attention of the Gla- morganshire farmers to the increased cultivation of it, and a great proportion of the best pastures were turned over by the plough — cattle were almost entire- ly neglected. . . . The natural consequence of inat- tention and starvation was, that the breed greatly de- generated in its disposition to fatten, and, certainly, with many exceptions, but yet as their general char- acter, the Glamorganshire cattle became and are flat- sided, sharp in the hip-joints and shoulders, high in the rump, too long on the legs, with thick skins, and a delicate constitution." ^ " It is well known that defective sanitary arrange- ments in the dwellings of the poor may, by primarily affecting the parents, impair the physical development of their offspring, and that congenital deformities are, for example, sometimes the result of the continued deprivation of light, which thus indirectly induces an arrest of development, such as can be produced direct- ly and at will in the case of tadpoles, which, in the absence of light, fail to become frogs." ^ " The effect of darkness in producing deformities is well illustrated in the case of the French historical painter, Ducornet, who used to paint with his feet, having been born without arms, of poor parents living in one of the dark caverns under the fortifications of 1 Youatt on "Cattle," p. 61. 2 Sedgwick, in British and Foreign Medico- Chirurgical Review, July, 1863, p. IH. 106 PRINCIPLES OF STOCK-BREEDING. Lille. It appears that several of the deformed beg- gars in Paris had also been born at Lille, and that the effect of the absence of light in these underground places, in producing malformed births, was so notori^ ous that the magistrates of Lille issued strict orders to prohibit the poor from taking up their abode in them." ' Variations frequently occur in particular locahties, that cannot be explained on account of the obscure action of the agencies that produce them. Such va- riations are said to be the result of endemic influences, which is a convenient name for local agencies that are not as yet fully understood. As an illustration of the obscure action of endemic causes of variation, the following examples are given : In the case of a family which dwelt alternately at Paris and Bordeaux, " the children engendered at Bordeaux were all bom deaf-mutes ; the children en- gendered at Paris were all endowed, as their parents, with perfect integrity of hearing. And this endemic influence is still more clearly shown in the case re- corded by Puybonnieux (' Mutisme et Surdite,' p. 30, 1846), of a married couple with eight children, of whom five were deaf-mutes; four of these last and two children who could speak were born at Kebre- chien, at a house called Le Jen de Paume, situated near the forest of Orleans, in a place elevated and ap- parently healthy ; nevertheless, the people who had dwelt there before the married couple referred to, had had three children, of whom two were deaf-mutes." ^ ' 3fedical Gazette, vol. x., p. 848, 1832 ; quoted by Sedgwick in foot- note, loc. cit., p. 174. 2 British and Foreign Medico- Chirurgical Review, July, 1863, p. 176. VARIATION. 107 The development of special characters in onr do- mestic animals, and their consequent improvement in a particular direction, is apparently limited by the ten- dency to diverse variations, from the increased sensi- tiveness of the organization to the influence of modi- fying agencies, and the defective equilibrium of the organization arising from the excessive predominance of a single character. If a variation in a special direc- tion is made at the expense of constitutional vigor, integrity of the nutritive organs, and fecundity, it be- ^comes an abnormal character that cannot be perpetu- ated/ ^ Inherited characteristics may for a time antagonize and keep in check the tendency to variation that arises in a change of surrounding conditions. Heredity tends to perpetuate the established habits, and is thus brought in conflict with the influences of the new environment. The latter will, however, prevail, unless particular care is taken to strengthen the hereditary proclivity by vigorous and systematic selec- tion. This struggle of diverse tendencies is " curiously illustrated in the case of some Australian acacias that were introduced to theNeil- gherries of India in 1845. At home these ti-ees flower in October, which is there a spring month. The transplanted acacias continued in India to flower in October till about 1860, when they were observed to flower in September ; in 18V0 they flowered in August ; in 1878 they flowered in July ; and lastly, in 1882, they began to flower in June, the spring month which corresponds most nearly with the Australian Oc- tober. The trees imported since 1845 have not yet gone so far back in the time of their flowering." {Popular Science Monthly, April, 1883, p. 864.) CHAPTEE YIII. FECUNDITY. _ The conditions of the animal organization that have an influence upon the function of reproduction seem to require more than a passing notice. The fer- tility of animals is frequently influenced by changes in their surroundings and habits that cannot, in them- selves, be considered unfavorable to the healthy action of the system. It has been observed that the procreative powers are impaired, or even entirely wanting, in many wild species, when placed in confinement. The elephant, the tiger, squirrels, monkeys, parrots, and many other animals, it is said, rarely, if ever, breed when subject- ed to man's control. Mr. Darwin, on the authority of Mr. Bartlett, records the remarkable fact that " lions breed more freely in traveling collections than in the Zoological Gardens." ^ The flying-squirrel, when breeding in captivity, has not been known to produce more than two young at a birth, w^hile in a state of nature it produces from three to six.^ " The African ostrich, though perfectly healthy * "Animals and Plants under Domestication," vol. ii., p. 185 ^ Darwin, loc. cit., p. IST. FECUNDITY. 109 and living long, in tlie south of France never lays more than from twelve to fifteen eggs, though in its native country it lays from twenty-five to thirty." ^ Lord Somerville says the Spanish mermo sheep, in England, when first imported, had a tendency to barrenness and " there was a great deficiency of milk in the ewes," "" which he attributes to the severe jour- neys the sheep were accustomed to make in Spain. As a deficiency in the secretion of milk and a ten- dency to barrenness have not been observed in these sheep when removed to other countries, these defects in England must have been owing to a change in the conditions of hfe, rather than to a previous habit of the system. According to M. Roulin, " in the hot valleys of the equatorial Cordilleras, sheep are not fully fecund," and geese, taken to the lofty plateau of Bogota, did not at first breed well.' Mr. Darwin says : " In Europe close confinement has a marked effect on the fertility of the fowl : it has been found in France that, with fowls allowed con- siderable freedom, only twenty per cent, of the eggs failed ; when allowed less freedom forty per cent, failed ; and, in close confinement, sixty out of the hundred were not hatched." * Mr. Darwin was assured that "those animals which usually breed freely under confinement, rarely 1 Darwin, loc. cit, p. 191. * Somerville's " Facts and Observations," p. 14 ; quoted in Youatt on "Sheep," p. 181. 3 " Animals and Plants under Domestication," vol. ii., p. 197. * Zoc, cil,, p. 198. 110 PRINCIPLES OP STOCK-BREEDING. breed, in the Zoological Gardens, within a year or two after their first importation,*' and he adds that, " when an animal which is generally sterile under confinement happens to breed, the young apparently do not inherit this power, for, had this been the case, various quad- rupeds and birds, which are valuable for exhibition, would have become common." ^ " The carnivora in the Zoological Gardens were formerly less freely exposed to the air and cold than at present ; and this change of treatment, as I was as- sured by the former superintendant, Mr. Miller, great- ly increased their fertility." ^ From the preceding statements it might be in- ferred that the state of domestication was not favor- able to fertility; but we find, nevertheless, that do- mesticated varieties are more prolific than w^ild species. Tame geese and ducks lay many more eggs than wild ones. Dogs have a larger number of young at a birth than their wild cousins, the wolf and the fox. The tame varieties of swine are more prolific than wild species. " The wild rabbit is said generally to breed four times yearly, and to produce from four to eight young ; the tame rabbit breeds six or seven times yearly, and produces from four to eleven young." "Wild pigeons do not breed so often as tame varie- ties, and Macgillivray states that, while the wild rock- pigeon breeds but twice a year. " the same pair, when tamed, generally breed four times." ' * Zoc. cii., p. 195. 2 Ibid., p. 185. ^ "Principles of Biology," vol. ii., p. 467; "Animala and Plants under Domestication," vol. ii., p. 139. FECUNDITY. HI The greater fecunditj of domesticated varieties, as compared witli tliat of wild species, is, in great measure, owing to a better supply of food throiigliont the year, and the more uniform conditions in which they are placed. The activity of the reproductive organs is neces- sarily dependent upon the function of nutrition which supplies the materials concerned in its operations. Dr. Carpenter says, " There is a certain degree of antagonism between the nutritive and the generative functions, the one set being executed at the expense of the other." ' A certain activity of the nutritive functions is re- quired to secure the greatest fertility in both plants and animals. When the function of nutrition is im- paired by disease, or when the supply of food is not sufficient for the wants of the system, the reproduc- tive powers suffer a corresponding decrease in their activity. Sheep bred on rich pastures are more likely to produce twin lambs than those gaining a scanty sub- sistence in less favored localities. It is said that, "among the barren hills of the west of Scotland, two lambs will be borne by about one ewe in twenty, whereas in England something like one ewe in three will bear two lambs." " While full feeding seems to increase the fecundity of varieties, any excess in the nutritive activity of the system will as readily impair the powers of reproduc- tion. * "Comparative Physiology." p. 147. * "Principles of Biology," vol. ii.. p. 459. 112 PRINCIPLES OF STOCK-BREEDING. In flowering plants, "it is well known that an over-supply of nntriment will cause an evolution of leaves at the expense of the flowers, so that what actu- ally would have been flower-buds are converted into leaf -buds ; or, the parts of the flower essentially con- cerned in reproduction, namely, the stamens and pistil, are converted into f oliaceous expansions, as in the pro- duction of ' double ' flowers from ' single ' ones by cul- tivation ; or, the fertile florets of the ' disk,' in com- posite species, such as the dahlia, are converted into the barren but expanded florets of the 'ray.' And the gardener who wishes to render a tree more pro- ductive of fruit is obliged to restrain its luxuriance by pruning, or to limit its supply of food by trenching around the roots." " During the period of rapid growth, when all the energies of the system are concentrated upon the per- fection of its individual structure, the reproductive system remains dormant, and is not aroused until the diminished activity of the nutritive functions allows it to be exercised without injury to them." ^ "While the period of rapid growth is not favorable to the development of the reproductive powers, from the great preponderance in the system of the nutritive functions, it will also be found that any marked de- ficiency in the processes of nutrition, as in the decline of life, will result in a decrease and final loss of fer- tility. The age of an animal will thus have an impor- ^ Carpenter's " Comparatire Physiology," p. 14Y. Root-pruning, as a remedy for " unf ruitfulnesse in trees," was recommended by Sir Hugh Plat, in his " Garden of Eden," fifth edition, published in London, 1659, p. 162. FECUNDITY. 113 tant influence on f ecnndity, tlirougli tiie variations in- volved in the nutritive functions. In a preceding chapter (page 36) the relations of age to fecundity have been noticed, in discussing the influence of immaturity in the parents upon the de- velopment of their offspring. It was there shown that the eggs of young animals were comparatively small and few in number. The sow and the bitch, breeding at an early age, have comparatively few young in a litter ; at the pe- riod of maturity the number reaches a maximum, and, at an advanced age, the number is diminished. " The young hamster produces only from three to six young ones, while that of a more advanced age produces from eight to sixteen." ^ Similar variations in the number of young at dif- ferent ages have been observed in other animals. The quality of food seems to exercise an influence on the reproductive functions, but the data for a full discussion of the subject are as yet wanting. In the development of the bee, the form of the cell and the character of the food determine the fertility or non- fertility of the perfect insect, and it is also claimed that in insects the sex is, in some cases, determined by the process of nutrition.'* A large proportion of sugar in the food is supposed to interfere with the reproductive functions.'' Prof. Tanner, in his paper on the reproductive powers of animals, says : " The general system of diet * "Principles of Biology," vol. ii., p. 438. ^ TJie Popular Science Monthly^ April, 1874, p. 761. ^ Journal of the Royal Agricultural Society^ 1865, p. 267. 6 114 PRINCIPLES OF STOCK-BREEDING. must also be looked upon as taking its share in influ- encing the reproductive functions. When the faU of rain has been small, and the herbage more than usu- ally parched, we find unusual diflSculty in getting ordi- nary farm-stock to breed — a dry dietary is very un- favorable for breeding animals, and very much retards successful impregnation. On the other hand, rich, juicy, and succulent vegetation is very generally favor- able to breeding. Apart, therefore, from the direct influence of the food given, it is certain that the con- dition in which it is consumed materially influences the breeding powers." ^ Mr. Mills, in his " Treatise on Cattle," published in 1Y76, remarks that " mares which have been brought up in the stable on dry food, and afterward turned to grass, do not breed at first ; some time is required to accustom them to this new aliment." ^ In the wild species that breed twice a year it has been stated that the time of breeding is determined by the abundance of food ; but this does not appear to be the case with migratory birds, in which the im- pulse to nest-building and migration occur together, at an early period in the spring, before they can ob- tain an abundant supply of food. There seems to be a marked relation between the size of animals and their fecundity, which may per- haps be owing, in part at least, to the modifying influ- ence of the nutritive functions. Throughout the en- tire animal kingdom the small species of animals ap- pear to be more prolific than large ones, and, as a rule, * Journal of the Royal Agricultural Sodety^ 1865, p. 269. 2 Loc. cit., p. 66. FECUNDITY. 115 they breed at an earlier age, and at shorter intervals, and produce a greater number of young at a birth. The elephant, the rhinoceros, the hippopotamus, the camel, and the dromedary, produce but one at a birth ; the cow, the red-deer, the sheep, the llama, the mare, and the ass, produce onfe or occasionally two; the goat, the roe-deer, and the chamois, produce two or three; the cat, the fox, the jackal, the tiger, the lion, and the bear, produce from two to six ; the dog and the wolf, from Rye to ten ; the wild-boar, from four to ten ; and the domestic sow, from eight to sev- enteen ; while the smaller rodents have produced as many as nineteen young at a birth. The larger animals, as the great pachyderms, the solipeds, and the ruminants, breed but once a year; while the smaller mammals breed two or three times in a year.' Among mammals, swine, and a few domesticated varieties, present almost the only exceptions to the prevailing inverse relation of size to fecundity. The larger birds are less prolific than the smaller species, while among the most minute members of the ani- mal kingdom the most astonishing fecundity is ob- served. In the cases of diminished fecundity from over- feeding, or from an abnormal activity of the nutritive functions, a plethoric condition of the system is pro- duced that may, in itself, impair the vigor of the re- productive powers, or lead to the development of local * Colin, "Physiologie comparee," tome ii., p. 531 ; Spencer's "Prin- ciples of Biology," vol. ii., pp. 435, 436; "Animals and Plants under Domestication," vol, ii., p. 139. 116 PRINCIPLES OF STOCK-BREEDING. congestion and inflammation that interfere with the activity of the function. In quite a number of cases of barrenness, in highly- fed and plethoric animals, that have come under my observation, the defect was clearly attributable to an extreme irritability of the organs of generation, result- ing from congestion or local inflammation. In some of these cases congestion of the mucous membrane of the vagina and mouth of the uterus was the only abnormal peculiarity that could be detected, while in others there was congestion of the ovaries, or deposits of tuberculous matter involving a large pro- portion of their tissues. In this connection, we should not overlook the fact that the highly-artificial conditions to which animals are subjected, to secure the development of special characters, render the system exceedingly sensitive to the influence of the acknowledged causes of the scrofu- lous habit. Even when the unsymmetrical development of the organization does not proceed far enough to produce an unhealthy condition of any of the reproductive organs, it may constitute a predisposing tendency to disease that is -liable to be made active by slight ex- citing causes. A long series of derangements of the organs of generation, of every grade of intensity, may thus arise, directly or indirectly, through the influence of the de- fective equilibrium of the system, produced by pam- pering and over-feeding. If the procreative functions are impaired by a plethoric condition of the system, without complica- FECUNDITY. 117 tions from local disease, tlie defect may be corrected in many instances by active exercise, low diet, or deple- tion ; but when tlie local derangements of the system are the result of disease it will be difficult to restore the normal activity of the function, even under the most skillful treatment. A remarkable development of the tendency to lay on fat is usually accompanied by a delicacy of consti- tution, a diminished secretion of milk, and a loss of fecundity. It is a popular notion that very fat animals are not likely to be good breeders, and when, even in flocks and herds that are not highly bred, a marked ten- dency to lay on fat is observed in precocious females, their ability to breed is often called in question. The general prevalence of such opinions seems to indicate that experience has shown that the excessive produc- tion of fat is incompatible with a high development of the reproductive powers ; and it is for this reason that objections are made to what is called " show con- dition " in breeding stock. Prof. Tanner, one of the best authorities on this subject, says : " The non-impregnation of the female may generally be traced to an excessive fatness in one or both of the animals, and an absence of constitu- tional vigor. The breeding powers are most energetic when the animals are in moderate condition, uninflu- enced either by extreme fatness or leanness." ^ The antagonism of the reproductive functions and the " fatty diathesis " is shown in the fact, well known to feeders, that the removal of the ovaries of the fe- * Journal of the Royal Agricultural Society, 1865, p. 266. 118 PRINCIPLES OF STOCK-BREEDING. male, or of tlie testicles of tlie male, gives an increased tendency to fatten. The influence of an excessive deposition of fat in tlie tissues upon the general health and activity of the system is thus referred to by Dr. Cragie, in liis paper on " Adipose Tissue : " " In persons of this description, who, it is matter of common observation, are generally not only pleth- oric but bloated, and liable to imperfect circulation, and disorders of the circulation and secretions gener- ally, and in whom very slight causes often induce serious disorders, the adipose tissue appears to lose a great proportion of the small degree of vital energy which it possesses ; and the more abundant its secreted product is, the less active are its vessels and the in- herent properties of the membrane. " In consequence of this greatly-impaired energy, slight causes, as cold, injury, punctures, etc., produce suddenly a complete loss of circulation and action in the tissues — for it is not increased but diminished action — and this impaired energy continues until the natural function of the tissue becomes extinct." As to the formation of fat, he adds: "In females and eunuchs it is more abundant than in males; in fe- males deprived of the ovaries it is more abundant than in those possessed of those organs, and it is well known that sterility is frequent among the corpulent of both sexes." ^ In many instances the integrity of important or- gans is impaired by deposits of fat, or by the actual transformation of their substance into fatty tissue, * " Cyclopsedia of Anatomy and Physiology," vol. i., p. 62. FECUNDITY. IJ^g whicL. is known to medical men as " fattj degenera- tion." Dr. Carpenter says : " There is one remark- able form of degeneration, however, wliich is common to nearly all tissues, and wMch seems to occur, as a normal alteration, in many of them at an advanced period of life ; this consists in the conversion of their albuminous or gelatinous materials into fat, thus con- stituting what is known as fatty degeneration. That this change is not due to the removal of the normal components of the tissues, and the substitution of newly-deposited fatty matter in their place, but is (in most cases at least) the result of a real conversion of the one class of substance into the other, has been already pointed out;" and he further remarks that " there is reason to believe that ' fatty degeneration,' the form under which degeneration most commonly presents itseK, is in reality far more frequent than simple wasting of the tissues ; but it attracts less no- tice because their bulk is little or not at all diminished, and it is only when their function becomes impaired that attention is seriously drawn to the change." ^ Dr. Flint, one of the best authorities on the sub- ject of physiology, says fat " does not take part in the nutrition of the parts that are endowed, to an eminent degree, with the so-called vital functions ; and, when these tissues are brought to the highest point of func- tional development, the fat is entirely removed from their substance. Long disuse of any part wiH produce such changes in its power of appropriating nitrogen- ized material for its regeneration that it soon becomes atrophied and altered. Instead of the normal nitro- * "Human Physiology," pp. 553, 659. 120 rrviNCiPLEs op stock-breeding. genized elements of tlie tissue, we have, iiiider these circumstances, a deposition of fatty matter. The fat is here inert, and takes the place of the substance that gives to the part its characteristic function. These phenomena are strikingly apparent in muscles that have been long disused or paralyzed, or in nerves that have lost their functional activity. If the change be not too extensive the fat may be made to disappear, and the part will return to its normal constitution by appropriate exercise ; but frequently the alteration has proceeded so far as to be irremediable and per- manent." ^ The reproductive organs of very fat animals are frequently affected with fatty degeneration, to an ex- tent that impairs or entirely destroys their functional activity. In a valuable paper on " The Heproductive Pow- ers of Animals," Prof. Tanner says : " For the pur- pose of more fully investigating the causes of barren- ness, I have examined the ovaries of several heifers which were, after a very careful trial, condemned and killed as barreners, and I have every reason to believe that by far the larger proportion were naturally quite competent for breeding, and that, in the majority of cases, non-impregnation arose from the seminal fluid never reaching the ovum, which was ready for fertili- zation, or from that fluid not being of a healthy char- acter. " In some cases in which the ova were, to all ap- pearances, perfectly healthy, the tubes — ^whereby the seminal fluid should have been conveyed — were so ^ Flint's "Physiology of Man "—" Nutrition," p. 381. FECUNDITY. 121 overcharged with f attj matter that impregnation was rendered impossible. " In other cases the ovaries were in an unhealthy condition, either one or both having, to a great extent, wasted away. Sometimes one of the ovaries had been suffering from atrophy, and the other in such an irri- table and sensitive condition that it might be almost described as inflamed, and under such circumstances the formation of a healthy ovum could be scarcely ex- pected. In other instances the ovaries had become considerably enlarged, in consequence of a fatty de- generation of these organs having taken place." ^ It is to be regretted that the condition of these animals, in regard to fattening tendency and constitu- tional peculiarities, is not given in the above cases, as it would aid us in determining the cause of the ob- served pathological conditions. Of the cases of bar- ren females that I have had an opportunity to investi- gate, the defect was attributable, in about equal pro- portions, to fatty degeneration of the ovaries, scrofu- lous tumors of the ovaries, and congestion and chronic inflammation of the uterus and its appendages — all of which were apparently the result of an excessive de- velopment of the tendency to fatten. "When the fatty degeneration, or the scrofulous tumors, were confined to one ovary, its fellow was usually the seat of congestion or chronic inflammation, and thus unfitted to develop a healthy ovum. From the correlated relations of the functions of nutrition and reproduction, it will be seen that great activity of the fat-producing functions, even when not * Journal of the Royal Agricultural Society^ 1865, p. 266. 122 PRINCIPLES OF STOCK-BREEDING. accompanied by local disease, will involve a corre- sponding decrease in the activity of the reproductive powers. From the antagonistic conditions presented in the law of correlation, it will perhaps be impossible to secure the highest type of perfection in the produc- tion of fat without impairing, to some extent at least, the functions of the reproductive organs. We have already noticed the apparent incompati- bility of the fat and the milk producing functions, and we find also that a diminished secretion of milk is often observed in animals that are not prolific, while the best breeders are usually good milkers. Prof. Tanner, in his paper which we have already noticed, says ; " The formation of milk is intimately connected with the reproductive powers. The secretion of milk is dependent upon the activity of the mammary glands, and these are either under the direct influence of the breeding-organs, or else they sympathize very closely with them. Those animals which breed with the least difficulty yield the best supplies of milk, and produce the most healthy and vigorous offspring. " l!Tow, it must be admitted that, however much we have improved the symmetry and feeding power of stock, we have suffered them to deteriorate in value as breeding animals, by the decrease of their milking capabilities. In proportion as we adopt a more natu- ral system of management, for the purpose of keeping stock in a healthy and vigorous breeding condition, so shall we reap the indirect benefit of a better supply of milk. It is true that a deficiency in the yield of milk may be met by other resources, but, since a short sup- FECUNDITY. 123 plj of milk is indicative of, and associated with, en- feebled breeding powers, every care should be taken to obviate this defect." ^ In the human family, as the physical organization, in structm-e and function, does not essentially differ from that of the lower animals, the same causes of impaired fertility will be operative, if the habits and conditions of life do not present a wide departure from those that prevail in a state of nature. With an advance in civilization, however, when the mental faculties attain a high degree of develop- ment, and the physical activity of the system is inten- sified through the action of the nervous system, a new element of variation is introduced, that disturbs the equilibrium of the system and increases the activity of the various causes that interfere with the procrea- tive functions. In a work published nearly one hundred years ago, Dr. Black remarked that " high refinement is an ob- stacle to propagation." In a paper read before the Statistical Society, in 1843, Sir John Boileau says : " It is a fact that rich families, taken in general, are those which have the fewest children ; and their ranks would become thinner, generation after generation, if they were not gradually recruited by new families of recently-acquired wealth. " The effect which riches have in restraining the fecundity of marriages is nowhere more apparent than in Paris. The most opulent families of France con- gregate there, and, as they select certain quarters of the town for their residence, the facts brought out in * Journal of the Royal Agricultural Society^ 1865, p. 270. 124: PRINCIPLES OF STOCK-BREEDING. them are more remarkable and complete than any- where. " I^ow, by the investigations made tinder the di- rection of the Comte de Chabrol, the average of births to a marriage is, in the different arrondissements, in regular inverse proportion to the easy or opulent cir- cumstances of the population. In the first four ar- rondissements united, which are those where the most opulent families reside, the number of children to a marriage is only 1.97 ; that of the four poorest arron- dissements, on the contrary, is 2.86 ; and the differ- ence between the two arrondissements placed at the extremities of the scale is as 1.87 to 3.23, or more than 73 per cent. " These facts deserve the more attention because, in spite of the reasons which determine the inhabitants of Paris to choose peculiar localities, according to their respective circumstances, some poor families will be found in the quarters inhabited by the rich, and some rich families in the quarters occupied by the poor ; which fact necessarily diminishes the difference we should establish if it were possible to separate com- pletely the different classes of the population. We arrive at this important consideration that, if the second, third, tenth, and first arrondissements, where the richest famihes in Paris reside, were not continu- ally recruited from families freshly acquiring wealth, the actual number of inhabitants would not be main- tained. JN'ot only the children born there are less numerous than their parents, but, as we must deduct those who die in infancy, or who never marry — and that we must estimate these at least at a quarter of FECUNDITY. 125 the whole, in a town where thirteen children out of twentj-nine do not live to twentj-one — it follows that in three generations, or the space of a century, the population would be reduced to half its num- ber." Mr. G. R. Porter, in his " Progress of the !Kation," sajs, " Frequently, and indeed almost always, in old- settled countries, the proportionate number of births decreases with the advance of civilization and the more general diffusion of the conveniences and luxu- ries of life." ^ Other wi-iters speak of the generally acknowledged influence of the plethoric condition of the system that prevails among the wealthy, in producing diminished fecundity. It does not, however, follow from the facts stated that privation and want are favorable to fertility, as the reverse is true. It is a well-known fact that famines not only diminish population by an increased death-rate, but also by a diminution of the birth-rate.^ In the absence of those special conditions that an- tagonize the procreative functions, the greatest fecun- dity may be expected when the food-supply is suffi- cient for the wants of the system, and active habits of life conduce to a healthy performance of the various organic functions. There are facts that seem to show that an improved condition of the system, resulting from a better food- supply after a period of privation and even of disease, ^ The last three quotations have been copied from Walford's " In- surance Cyclopaedia," vol. iii., pp. 185, 190. ^ Walford, " Insurance Cyclopaedia," vol. iii., p. 163. 126 PRINCIPLES OF STOCK-BREEDING. may produce an uimsiial activity of tlie functions of reproduction. The unusually rapid increase of population, after a country lias been scourged by a famine or pestilence, has often been remarked. After the plague of 1348 in England, the " flocks and herds wandered about at will, without herdsmen, shepherd, or owner," and labor was so scarce that landlords were glad to have their lands cultivated by their tenants without payment of rent. Population, however, speedily righted itself. " We are told that after the plague double and triple births were fre- quent, that most marriages were fertile, and that no serious effects were produced, in a short time, on the numbers of the people." ^ In examining the various causes of impaired fe- cundity, we must not lose sight of the influence of the transmission of ancestral tendencies and peculi- arities. If the ancestors of an animal are not prolific, it will inherit a bias of the organization that is favorable to the action of the various causes of sterility and bar- renness ; that is, the natural tendency or predisposi- tion of the organization will, as it were, add to the intensity of the forces that interfere with the normal performance of the function of reproduction, and thus aid in its suppression. The production of twins will be found to depend, not only upon the supply of food, as already noticed, but on pecuharities of the system that have been in- herited. * Rogers, " History of Agriculture and Prices," vol. i., pp. 299-301. FECUNDITY. 127 " Osiander ^ relates the case of a woman who, in eleven accouchements^ had given birth to thirty-two children, was herseK born with three other twins, and her mother had had thirty-eight children ; another woman, delivered of five children at a birth, had a sister who was delivered of three ; and lately at Rouen, twin sisters gave birth to twins on the same day.'* Mr. J. Lewis Brittain ' related last year, at the Edinburgh Obstetrical Society, the case of a woman who had twins eleven times, and whose mother had had twins twice ; and the report states that ' several of the members mentioned that they knew of some analogous cases.' " '' Dr. Mitchell, in a paper on ' Plural Births in Con- nection with Idiocy,' * cites the following cases : The mother of an idiot, twin-born, bore twins twice, the maternal grandmother once, one maternal aunt twice, another once, and a sister once ; in a second case the mother was herself one of twins, and she bore twins once, and, in a third case of a twin-born idiot, the aunt had borne twins ; while among the cases in which the idiot was not twin-born, in one the mother and the maternal grandmother each bore twins twice ; in a second case the mother and the maternal grand- mother each bore twins once, and a maternal aunt twice ; in a third case the mother and three maternal aunts each bore twins once ; in a fourth case the mother bore twins once, and a maternal aunt bore ^ "Handbuch der Entbindungskunst," Band i., pp. 316, 317. ^ British Medical Journal, November 30, 1861, p. 598. ^ Edinburgh Medical Journal, 1862, p. 468. * Medical Times and Gazette, 1862, p. 618. 128 PRINCIPLES OF STOCK-BREEDING. twins four times running ; and in a fiftli case the mother and two sisters of the idiot each bore twins once. " It is also well known that the hereditary produc- tion of twins in sheep is encouraged bj saving the ewe-lambs that are twins. ^ l^otwithstanding these facts, there are some cases which show that twins oc- casionally owe their descent as such to the male line, of which the following case affords a good illustra- tion : Two brothers (twins) both had twins by their wives many times in succession ; the wife of one of them having died, the second wife produced, like the first, twins ; ^ and, in the case recorded by Mr. Stocks,' of Salford, twin brothers also produced twins ; one of them having a family of ten children, eight daughters and two sons, all of whom were twin-born ; and the other a family of eleven children, of whom eight were twin bom ; it is, moreover, to be noticed that in this last case, while five of the female twins in the suc- ceeding generation produced twins at their first birth, the three children of the only one of the male twins of whom any account is given, were all born singly, leading us to infer that the hereditary predisposition to twins was probably derived from a female ances- tor, and that each of the twin brothers referred to, in addition to being the medium of transmission, also shared in the inheritance. " In connection also with the influence of sex in the 1 "Notes on Fields and Cattle," by Rev. W. H. Beever, 1862, p. 144. 2 "Nouvelle Dictionnaire d'Histoire Naturelle," tome xii., p. 6^6. 3 Lancet, July 20, 1861, p. '78. FECUNDITY. 129 production of twins, it is necessary to notice the popu- lar error respecting the alleged barrenness of females who have themselves been bom as twins with male children, for it is still customary among nurses and midwives, in some places, to talk somewhat disrespect- fully of such females, as disqualified for the marriage state, in consequence of their supposed inability to have children. " This error, which probably arose from the well- established fact of the barrenness of the free-martin (the imperfect cow-calf twin with a bull-calf), was re- futed by Mr. Cribb, in a paper published in 1823,^ which contains six cases of such females becoming mothers. " Dr. Sieveking has informed me of a case in which a woman, twin with a male, subsequently gave birth to twins ; and any remaining doubt on the subject is removed by the fact that such females have on some occasions become even more than usually prolific, as in the case which occurred near Maidenhead,'^ of quad- ruplets, consisting of three boys and one girl, who were all reared, and the only female in this quartet subsequently became the mother of triplets, consisting of two boys and one girl." ' The following remarkable case would need to be well authenticated to entitle it to credence : " The 1 London Medical Repository, 1823, pp. 213-216. 5 Ibid., 1827, p. 350. 2 In the above quotation from Mr. Sedgwick's paper, British mid Foreign Medico- Chirurgical Revieii\ July, 1863, pp. lYO, 171, the origi- nal sources from which the cases were compiled are cited in the foot- notes. 130 PRINCIPLES OF STOCK-BREEDING. Boston Medical and Surgical Journal stated that on the 21st of August, 1872, Mrs. Timothy Bradler, of Trumbull County, Ohio, gave birth to eight children — three boys and five girls. They were all living and healthy, but quite small. She was married six years previously, and weighed two hundred and seventy-three pounds on the day of her marriage. She has given birth to two pairs of twins, and now eight more, making twelve children in six years. Mrs. Bradler was one of a triplet, her mother and her father being twins, and her grandmother the mother of five pairs of twins." ' " In a remarkable instance which occurred in the city of E'ew York, the mother had twelve children within four years after her second marriage, at four births, there having been twins at the first, triplets at the second and third, and quadruplets at the fourth. The first (twin) birth occurred at the age of thirty- five ; she had previously given birth to seven children, one only at a time." ^ " A still more remarkable case occurred in Mercer County, Pennsylvania, in 1816, ten children having been born within twelve months, five at each of two births. The mother died about a year after the second birth, but meantime gave birth to twins ; or twelve children in twenty months. She was thirty-seven years old at her death." ^ ^ British Ifedical Journal, November, 1872, as quoted in "Walford's "Insurance Cyclopaedia," vol. iii., article "Fecundity," p. 200, where a large number of cases of multiple births are recorded, including twen- ty-five cases of triplets, thirteen of quartets, three of quintets, and one each of six, eight, and ten, at a birth. * Dr. E. R. Peaslee, Johnson's " Universal Cyclopaedia," article "Gestation." » Ibid., loc. cit. FECUNDITY. 131 " An instance is mentioned in the Bulletin des Sci- ences of a cow belonging to a French agriculturist, which produced nine calves at three successive births, namely, four at the first, three at the second, and two at the third ; all of which, except two of the first birth, grew up and were nursed bj the mother ; but the heif- ers afterward produced each only a single calf." ^ According to CuUey, the Teeswater ewes " gener- ally bring two lambs each, and sometimes three ; there are instances of even four or five, as was the case with Mr. Edward Eddison's ewe, which, when two years old, in 17Y2, brought him four lambs ; in 1773, five ; in 1774, two ; in 1775, five ; in 1776, two ; and in 1777, two. The first nine lambs were lambed within eleven months." ' A ewe belonging to James Wilkie, Esq., of the county of Berwick, Scotland, " produced eleven lambs in the course of three immediately succeeding seasons. In the spring of 1803, she had four lambs ; in 1804, three ; and again four in 1806. She was of the or' dinary breed of the lower part of the country." * Mr. Kerr remarks in regard to these sheep that " ill-fed ewes hardly ever have twins, while those that are in good condition, when put to the ram, very often have twins, and sometimes triplets." " In 1806, in a flock of ]N"orfolk ewes belonging to Mr. "Wythe, of Eye, one on the 18th of February yeaned three lambs ; on the 20th another dropped three, and a third, five, on the 21st ; a fourth, four, on the 23d ; ^ " British Husbandry," vol. ii., p. 438, note. 2 CuUey on " Live-Stock," p. 123. 3 Kerr's "Agricultural Survey of Berwickshire," p. 403. 132 PRINCIPLES OF STOCK-BREEDING. and on the same day a fifth produced three. On the 25th a sixth ewe dropped three lambs ; and a seventh yielded four on the 27th. So that seven ewes yeaned twenty-five lambs, all of which were reared." ^ " Last week a ewe, belonging to Mr. Kitter, yeaned five lambs ; she also brought five lambs last year, and four the year before ; i. e., fourteen lambs in three years, and not a weak or deformed one in the whole number." ^ "Mr. Meadows, of Salcey Forest, Northampton- shire, has a ewe which brought him three lambs in 1802, four in 1803, four in 1804, and four in 1805 ; being fifteen lambs in four years." ^ Some breeds of sheep, as the Mendip and Dor- sets, mentioned by Youatt, breed twice a year, and he gives the following instance in another breed : "In the spring of 1801, Mr. Sheriff, of Kinmyles, Inver- ness, bought a parcel of ewes in lamb, of the white- faced Highland breed. They lambed in March and April. One old ewe, without a tooth, dropped a second lamb on the 1st of J^ovember, 1801, a third on the^29th of April, 1802, and a fourth on the 12th of January, 1803 ; so that she reared four lambs at different times in the course of twenty-one months." * Rev. Gilbert White gives an account of a half- bred " Bantam " sow that was remarkable for her ' "Annual Register," 1806 ; quoted in Youatt on " Sheep," p. 509. 2 Gentleman's Magazine, March, 1*750 ; quoted in Youatt on " Sheep," p. 509. 3 Agricultural Magazine, April, 1804 ; quoted in Youatt on "Sheep," p. 509. * Agricultural Magazine, February, 1803 ; quoted in Youatt on " Sheep," p. 509. FECUNDITY. I33 fecundity and longevity : " For about ten years this prolific mother produced two litters in the year, of about ten at a time, and once above twenty at a litter ; but as there were near double the number of pigs to that of teats, many died. ... At the age of about fifteen, her litters began to be reduced to four or five, and such a litter she exhibited when in her fatting- pen. ... At a moderate computation, she was al- lowed to have been the fruitful parent of three hun- dred pigs — a prodigious instance of fecundity in so large a quadruped. She was killed in the spring of 1775, when seventeen years old." * A remarkable instance of multiple births is re- ported in the Prairie Farmer, on the authority of the London Live-Stock Journal, as follows : " In the neighborhood of Hohenmath, Bavaria, a cow has re- cently been delivered of ^nq calves at a birth. All of them were born dead, and the mother succumbed a few days later. The calves weighed sixteen, seven- teen, eighteen, nineteen, and twenty pounds, respec- tively, and were all of the same color." " Dr. Simpson states that he has obtained authentic information in regard to forty-two married women who were " born as twins with males," and thirty-six of the number had children. " Two of the females who have families were each born as a triplet with two males." ' ' "Natural History of Selborne," p. 222. "The Hog," by Youatt, p. 154. ^Prairie Farmer, December 8, 18'7'7, p. 389. These eases are, perhaps, not all attributable to heredity. For additional cases of in^ herited fecundity, see p. 16. 3 " Cyclopaedia of Anatomy and Physiology," vol. i., p. 736. 134: PRINCIPLES OF STOCK-BREEDING. Among cattle, where twin calves are produced, the one a male and the other a female, the latter, called a free-martin, is, as a rule, barren. When the twins are of the same sex, the reproductive powers are not impaired. In all other varieties of animals, so far as known, when males and females are born together as twins, the females are as prolific as if born singly. In free- martins the internal generative organs are generally imperfect, partaking of the characters of both male and female organs. In appearance these imperfect females frequently resemble steers, the feminine char- acteristics being mostly wanting.^ In rare instances the free-martin is capable of breeding, the reproductive organs not having become malformed from her intra-uterine development with a male. Youatt, in his work on " Cattle," gives but two cases of fertile free-martins. Dr. Hunter dissected a free-martin calf, that died when a month old, and found the sexual organs naturally constituted, and he also heard of two instances in Scotland of free-martins that were prolific. Dr. Maulson has likewise published similar cases in Loudon's Magazine of Natural History.^ A few additional cases might be gathered from the agricultural papers, but they only serve to show that fertility under such conditions is decidedly ex- ceptional. * " Cyclopaedia of Anatomy and Physiology," vol. ii., pp. '701, 702, TSS, 736. Youatt on " Cattle," p. 538. * " Cyclopeedia of Anatomy and Physiology," vol. ii., p. 735. FECUNDITY. I35 Dr. Simpson, in liis valuable paper, from wliich we have already quoted, says : " As to the cause of the malformation and consequent infecundity of the organs of generation in the free-martin cow, we will not venture to offer any conjecture in explanation of it. " It appears to be one of the strangest facts in the whole range of teratological science, that the twin existence in utero of a male along with a female should entail upon the latter so great a degree of malformation in its sexual organs, and in its sexual organs only. The circumstance becomes only the more inexplicable when we consider this physiologi- cal law to be confined principally, or entirely, to the cow, and certainly not to hold with regard to sheep, or perhaps any other animal. The curiosity of the fact also becomes heightened and increased when we recollect that when the cow or any other uniparous animal has twins, both of the same sex, as two males or two females, these animals are always both perfect- ly formed in their sexual organization, and both ca- pable of propagating. In the course of making the preceding inquiries after females born co-twins with males in the human subject, we have had a very great number of cases of purely female and purely male twins mentioned to us, who had grown up and be- come married ; and in only two or three instances, at most, have we heard of an unproductive marriage among such persons. Further, we may in conclusion remark that, among the long list of individual cases of hermaphroditism in the human subject that we have had occasion to cite, we find only one instance 136 PRINCIPLES OF STOCK-BREEDING. in whicli the malformed being is stated to have been a twin. Katsky, however, Nargele, and Saviard, have each, as before stated, mentioned a case in which both twins were hermaphroditically formed in their sexual organs." ' It is worthy of mention, in this connection, that some authors assert that the production of twins in the human species is an abnormal peculiarity, and they claim that a larger proportion of idiots and im- beciles are twin-born than of those not thus affected, that the relatives of imbeciles and idiots frequently have twins, and that, in families where twins are fre- quently produced, bodily deformities are repeatedly observed.'' Dr. Duncan, in his work on " Fecundity, Fertility, and Sterility," is inclined to the belief that the pro- duction of twins in the human family is not x)nly abnormal, but that it cannot be relied upon as an indi- cation of great fecundity, as twins are usually pro- duced at longer intervals than single births, and that in the latter the entire period of child-bearing is like- ly to be more extended. ^ Loc. dt.^ p. 736. 2 See Dr. Arthur MitcheH's paper in the Medical Times and Gazette^ November 15, 1862, referred to in Walford's "Insurance Cyclopaedia," vol. iii., p. 192. For further illustra,tions of the influence of civilization on fecun- dity, see an article on " Changes in New England Population," by Dr. Nathan Allen, in Popdar Science Monthly, August, 1883, p. 433. CHAPTEE IX. IN-AND-IN BEEEDING. The term in-and-in breeding is generally used to indicate the breeding togetber of animals that are closely related. As to the degree of relationship, in the breeding of animals, to which this term should be applied, it not only appears that no definite rule has been estab- lished, but that almost every writer uses it with a dif- ferent shade of meaning. The prevailing differences of opinion in regard to the effects of in-and-in breeding have, to some extent at least, arisen from this diversity of meaning in the use of the term, and a misapprehension as to the real advantages that are aimed at in its practice.^ * In-and-in breeding has been defined as follows : " The breeding from close affinities "— Youatt on " Cattle," p. 525. " The breeding from close relations" — Johnson's "Farmers' Cyclopaedia," p. 248. " Breeding between relatives without reference to the degree of con- sanguinity"— Eandall's "Practical Shepherd," p. 116. "It should only be applied to animals of precisely the same blood as own brother and sister " — Bowly, Journal of the Royal Agricultural Society^ vol. xix., p. 149. " Breeding from the same family, or putting animals of the nearest relationship together " — Sinclair's " Code of Agriculture," p. 93. " The pairing of relations within the degree of second cousins, twice or more in succession " — Stonehenge on " The Horse," p. 140. 7 138 PKINCIPLES OF STOCK-BREEDING. Sir John SebrigM, whose successful practice gives the weight of authority to his opinions on this subject, is often quoted as an opponent of in-and-in breeding. He evidently, however, limits the application of the term to the frequent repetition of the closest rela- tionship in parents. He says : " Mr. Meynel's fox- hounds are likewise quoted as an instance of the success of this practice ; but, upon speaking to that gentleman upon the subject, I found that he did not attach the meaning that I do to the term in-and-in. He said that he frequently bred from the father and the daughter, and the mother and son. That is not what I consider as breeding in-and-in, for the daugh- ter is only half of the same blood as the father, and will probably partake, in a great degree, of the prop- erties of the mother. "Mr. Meynel sometimes bred from brother and sister; this, certainly, is what may be called a little close / but should they loth le very good, and partic- ularly should the same defects not predominate in both, but the perfections of the one promise to cor- rect in tlie produce the imperfections of the other, / do not tJiink it oljectioncible : much further than this, the system of breeding from the same family cannot, in my opinion, be pursued with safety." ^ He then proceeds to point out the difficulties that arise, in the practice of what he calls in-and-in breed- ing, from the rare instances in which breeding-ani- mals are found to be free from defects. If the terms inbreeding, close breeding, and in- terbreeding, are used to indicate the breeding to- * " The Art of improving the Breed of Domestic Animals," pp. 8, 9. IN-AND-IN BREEDING. I39 getlier of closely -related animals in a single in- stance, or at long-separated intervals, the term in- and-in breeding could then be used with greater ex- actness to indicate the frequent repetition of the pro- cess. High breeding implies a careful selection of breed- ing-animals within the limits of a family, with refer- ence to a particular type, and regardless of relation- ships. High-bred animals are not necessarily in-and- in bred, although, from the system of selection prac- tised, they must be closely bred to a greater or less extent. The opponents of in-and-in breeding claim that it produces a delicacy of constitution — a predisposition to disease, and a lack of fecundity — and they often fall into the error of assuming that all who do not admit the truth of these claims are in favor of close breeding as a rule of practice. For the purpose of gaining, a knowledge of the principles involved in the breeding together of ani- mals that are closely related, we will first examine the practice of those who have gained a high repu- tation as breeders of domestic animals, and then consider the objections to their methods of improve- ment. From the time of Bakewell, the breeders who have gained the greatest reputation have evidently aimed to establish in their flocks and herds certain well-marked characters that adapted the animal to a particular purpose. In giving expression to their ideal type, or stand- ard of excellence, they found it necessary to limit 140 PRINCIPLES OF STOCK-BREEDING, their selection of breeding-stock to the animals that had the characters they wished to perpetuate. As it was only among the animals descended from a com- mon ancestry — with the same hereditary tendencies — that the desired variations were found, they were frequently compelled to breed together animals that were more or less closely related. Their selections were made to secure in both j)arents the same general characteristics that they wished to obtain in their offspring, and the close re- lationships observed in their breeding-stock were but the necessary incidents of their practice. Close breeding with them was but a Tneans of im- provement, and not an end that was thought to be desirable in itseK. The true method of improvement practised by these eminent breeders is frequently misunderstood, and their intentions have, consequently, been misrep- resented. A friend of mine, on his return from England, told me that he had learned an important secret in breeding that he believed to be a prevail- ing rule among the best breeders. It was this : "Breed from haK brother and sister;" and an ex- amination of a large number of the most celebrated pedigrees apparently made the theory a plausible one. An incidental feature in the methodical improve- ment of animals had, however, been mistaken for the real causes of improvement, which were entirely over- looked. Animals are not improved by breeding except in the increased stabiKty gained in dominant characters, IN-AND-m BREEDING. 141 and tlie certainty with wMcL. they are transmitted, as the offspring, at the time of birth, can only be pos- sessed of the characters they have derived from their ancestors. The true means of improvement have abeady been pointed out in the chapter on variation, and we must look upon methods of breeding solely with reference to the perpetuation of characters thus obtained. JSTo matter what opinions we may form as to the advantages or disadvantages of close breeding, the fact remains the same : that all the great breeders have practised it to a greater or less extent, and, as far as we are able to judge, with the same purpose — that of retaining and fixing in their floclvs and herds certain desirable characters that have been developed by mod- ified conditions. The extent to which in-and-in breeding has been practised by the breeders who have attained the great- est celebrity is shown in the accompanying diagrams.* The pedigrees in a number of the diagrams are arranged on a new plan; the name of each animal being given but once, while the lines are drawn so that the relationships can be readily traced. The pedigrees are selected to represent the most popular families of the leading breeds, as indicating ^ Some of these diagrams were prepared to illustrate a lecture on " In-and-in Breeding," delivered by the author before the "American As- sociation of Breeders of Short-Horns," at their meeting in Cincinnati, December 3, 1873, and published in their Transactions. The lecture and diagram were also published in the " Report of the Michigan State Board of Agriculture for 18'72." The illustrations have been made use of in this chapter, but the matter has been entirely rewritten and ar- ranged to conform to the classification of topics in this work. 142 PRINCIPLES OF STOCK-BREEDING. IN-AND-IN BREEDING. I43 the uniformity of the practice in the improvement of all classes of animals. In all of the cases cited, the breeders evidently in- tended to hreed together animals of the same qualities^ regardless of relationshvp. In Diagram 1, the pedigree of Duke of Airdrie may be traced, beginning with the six animals at the extreme left of the diagram. In Diagram 2, the pedigrees of these same six ani- mals, arranged in a different order, may be traced back to Favorite by black lines, while the dotted lines if continued would run to Hubback. Certain animals in Diagram 1 are arranged in a different order, and taken for the basis of Diagram 3, which gives the pedigrees of some of the " ITew York Mills "herd. Diagram 8 gives the pedigree of a number of ani- mals bred by Charles and Eobert Colling. In all of the diagrams, the two lines coming to- gether at the left of a name trace respectively to the sire and dam, while the lines from the right of the name run to the offspring. The Booths practised close breeding to a great extent, as will be seen from an examination of the pedigree of their most noted animals. The pedi- gree of the sisters Queen of the May, Queen Mab, Queen of the Yale, and Queen of the Ocean ; and their brother, Lord of the Yalley (14837), bred by K. Booth, of Warlaby, is given in Diagram 4, on page 147. According to the calculations of Bev. J". Stone, of Hellidon, "Crown Prince is 1055 times descended 144 PKINCIPLES OF STOCK-BREEDIXG. IK-AND-IN BREEDING. 145 146 PRINCIPLES OF STOCK-BREEDING. from Favorite, and Eed Rose by Harbinger, 13M times. So the produce of the two are descended from him 2399 times." ' Lord of the Yallej and his sisters are three six- teenths of the blood of Pilot, although he had not been used for five generations. They are also five-sixteenths of the blood of Buck- ingham. Lord of the Isles (18267) is an example of still closer breeding ; he was got by Sir Samuel out of Red Rose, by Harbinger. Sir Samuel was got by Crown Prince out of Charity, the dam of Crown Prince. Ac- cording to the same authority, the out-crosses made use of by Mr. Booth had a strong infusion of the blood of Favorite, Mussulman having sixty-four crosses, Lord Lieutenant one hundred and six crosses, and Matchem fifty-two crosses of this favorite progenitor of the improved Short-Horns. Diagram 7 shows the extent to which in-and-in breeding has been practised with the Heref ords. Mr. Price, the celebrated breeder of Heref ords, says : " I bought from Mr. Tompkins a considerable number of his cows and heifers, and two more bulls. I have kept the blood of these cattle unadulterated for forty years, and Mr. Tompkins assured me that he had bred the whole of his stock from two heifers and a bull, selected by himseK early in life, without any cross of blood. " My herd of cattle has, therefore, been bred in- and-in, as it is termed, for upward of eighty years, and by far the greater part of it in a direct line, on 'Carr's "History," p. 40. IN-AND-IN BREEDING. 147 rYonjig Matcliein (Cm). Set tOmh ftconard CRtC ii & ■s Bar«uTratIi!iy(tS15). J (YounsKcd RoTcr(«l)T). SuMinti UloMomM.j ainjeyiirt). feWoif, Ul;inJcr j^ , frilot(<»^ aiplierry (iSTSJ. £« Mm*. . fMa(clicm(42Sn, pflotpMJ. Ci-ualiuo. I mot (158}, tAnaODo. i \CaniaiIou. i AlbioH a^ f TonDU Albton 03). fErancaco (2035), fTonnj AUtlofi ps). rTcui)sAllIail(I3), ysuij. (Yonos Albion (Itl, rYouira iJbroD do Datliui, \ - -t { I I JPIloU««>. rfouDj f 1 Filol «»«}, Alblou ns). 'Yooag Albion (IS), rpuoiidO, a, fToiirjAIbioutisk fTomwArfi- rpiionoiii rfiVJUcianacrCSJI). rUot (4ose an individual yard in which this has been so far accomplished that in only a small proportion does the hated white feather appear. This desired result, with a little care, will now be easily maintained while such a yard is bred to itself, or with any other not too far removed from it in blood ; but if crossed from a strain thorougKly distinct and alien, or what poultry- men call too " sudden " a cross (for, without knowing the reason, they have found the evil of such often, and know it well), the old white feather may very proba- bly reappear in all its original strength, though the new blood contained no tendency to it whatever. It is simply the cross of strange blood which gives the impulse to reversion. In the same way, to take the case mentioned just now, the pure white Spanish face being simply the result of assiduous breeding, and the most extreme care being needed for its preservation, the simple fact of crossing two entirely distinct strains gives the impulse to revert to the red face which be- * Journal of the Royal Agricultural Society, vol. xxii,, p. 1 1. CKOSS-BREEDING. 207 longed to tlie Minorca — in all probability the original breed from wbicb it was derived." ^ The value of cross-bred animals for breeding-pur- poses is diminished by this tendency to reversion, and the consequent loss of the power of transmitting any definite characters to their offspring. It is generally admitted that, in the cases in which improvements are effected by crossing, the greatest change is produced by the first cross, and that the im- provement resulting from a repetition of the process is uniformly slight. This would undoubtedly be the case from the prin- ciples already presented : the greater the difference be- tween the two parents, when one of them is prepotent in the transmission of its characters, the greater would be the resemblance of the offspring to the one, and the wider the divergence from the characters of the .other parent ; and, as the resemblance of the parents to each other would be gradually increased by succes- sive crosses, the difference between the offspring and the inferior parent would as gradually diminish It is claimed that the tendency to develop undesir- able characters is increased by each successive cross ; ^ but the facts relating to this subject, in the history of the breeds that have been established by crossing, have not been recorded with sufficient exactness to furnish conclusive proof of the correctness of this opinion. It does not, however, appear to be improbable that such 1 " Book of Poultry," p. 126. 2 Journal of tJie Royal Agricultural Society, vol. xxiii., p. 352, vol. XX., p. 296 ; Quarterly Journal of Agriculture, vol. i., p. 178, vol. vii., p. 497; Sinclair's "Code of Agriculture," p. 95. 208 PRINCIPLES OF STOCK-BREEDING. may be tile case, from the fact that in each successive cross the relative potency of the pure-bred male would be diminished, as the females to which he is bred are improved in their characters. On the other hand, it might seem probable that the improvement of the female would increase the tendency to a predominance of the desired characters, and thus intensify the influence of the male in the further improvement of the family. But cross-bred animals do not, as a rule, transmit to their ofl'spring, as dominant characters, the peculiarities that they have derived from a superior breed, even when they appear to predominate in their organization. When both parents are cross-bred animals — even in cases in which they both resemble the superior race from which they have derived their most obvious characteristics — the prevailing tendency in their pow- ers of transmission is shown in the frequent recur- rence of remote ancestral characters in their offspring. In attempts to establish a new breed by crossing, this tendency to atavic transmission can only be over- come by a persistent and long-continued system of selection. " Changes, in fact, by crossing, are not to be effected in a short space of time ; you must look forward to several years of constant exertion, before you can hope, in this manner, to alter your stock." ^ Mr. Hogg says : " By the attempt which has been made to renovate the Scottish flocks by the Cheviot blood, we see the unexpected length of time necessary for completing and confirming the change. " No class of animals which I am acquainted with 1 Blacklock on "Sheep," p. 115. CROSS-BEEEDING. 209 adhere more tenaciously to family distinctions than sheep, and the longer the blood has been kept pnre and nnmixed with that of another family, the more powerfully do they resist a foreign connection ; and in the case under our immediate consideration, the opposition to a coalition of natures is doubly power- ful, as it is a forcing of the creature farther from a state of nature into one more artificial, more depend- ent, and more directly under the management of man. . . . After a course of twenty or twenty-five years, at which period the Cheviot peculiarities are got tolera- bly well-established, and every attribute of the old race seems to be completely suppressed, an individual lamb will, in some generations, still exhibit the wild air and shaggy coat of the ancient maternal line." ^ Sir John Sinclair remarks that, " as to any attempt at improvement by crossing two distinct breeds or races, one of which possesses the properties which it is wished to obtain, or is free from the defects which it is desirable to remove, it requires a degree of judg- ment and perseverance to render such a plan success- ful as is very rarely to be met with." "^ In summing up the arguments in favor of cross- breeding, Mr. Spooner says : ^ Although the benefits are most evident in the first cross, after which, from pairing the cross-bred animals, the defects of one breed or the other, or the incongruities of both, are perpet- ually breaking out, yet, unless the characteristics and conformation of the two breeds are altogether averse to each other, l^ature opposes no barrier to their suc- * Quarterly Journal of Agriculture, vol. i., pp. 176-1 '79. 2 "Code of Agriculture," p. 95. 10 210 PRINCIPLES OF STOCK-BREEDING. cessful admixture ; so thatj in the conrse of time, by the aid of selection and careful weeding, it is practi- cable to establish a new breed altogether/ . . . Let ns conclude," he then says, "by repeating the advice that, when equal advantages can be attained by keep- ing a pure breed of sheep, such pure breed should unquestionably be preferred ; and that, although cross- ing for the purposes of the butcher may be practised with impunity, and even with advantage, yet no one should do so for the purpose of establishing a new breed, unless he has clear and well-defined views of the object he seeks to accomplish, and has duly stud- ied the principles on which it can be carried out, and is determined to bestow for the space of half a life- time his constant and unremitting attention to the discovery and removal of defects." ^ From the variety of improved breeds that can now be obtained, adapted to almost every variety of climate and system of management, it cannot be desirable to attempt the formation of a new breed, as any special qualities that may be required under particular cir- cumstances can be more readily obtained by a modifi- cation of the characteristics of some existing breed that approximates in its qualities to the proposed standard. As cross-breeding among cattle, sheep, and swine, can only be recommended for the production of ani- mals intended for the butcher, it may be well to con- sider some of the advantages arising from its judicious practice for this purpose. ' Journal of the Royal Agricultural Society^ vol. xx., p. 311. ^ Loc. cit., p. 313. CROSS-BREEDING. 211 A large proportion of our farm-stock, for a long time to come, must necessarily consist of the so-called " natives " and the grades that have been produced from them bj various crosses. These animals have the advantage of hardiness, but they are not good feeders, and do not arrive at maturity at as early an age as the modern pure breeds. When crossed with the best of the meat-producing breeds, they are at once improved in these important qualities in which they were before deficient, while in the quality of their flesh they may be equal, if not superior, to the more highly-bred animals of the pure breeds. In the pure breeds in which the fattening qualities have been highly developed, an excessive activity of the formation of fat may be readily induced, in con- nection with a deficiency in lean flesh that diminishes the real value of the animal when it reaches its final destination on the block. The value of such animals consists in their ability to transmit to their offspring their general form, with the tendency to matm-e early and fatten rapidly. When such animals are crossed upon natives or grades of inferior quality, it is not surprising to see in their offspring a quality of flesh that in its propor- tions of lean and fat is superior to that of either par- ent. In speaking of a cross of the Lincoln and Leices- ter sheep, Mr. Mosscrop says : " The cross improves the size, the quantity of wool, and the quality of the mutton, although perhaps the distinguishing feature of the pure-bred Leicester — ^propensity to fatten at an early age — is somewhat impaired. 212 rKINCIPLES OF STOCK-BEEEDIXG. " The greater admixture of lean mutton, however, more than compensates for this, b j giving a superior value to the carcass." ^ In the cross of a superior breed upon the average stock of the farm, the best results can only be ob- tained by a better system of feeding than the original stock had been accustomed to. The old Scotch say- ing, that " the breed is in the mouth," expresses an important truth in stock management. An increase in size and the ability to fatten rapid- ly would become a source of weakness rather than an advantage in animals that are unable to obtain a suf- ficient supply of food to give a full and active devel- opment of the system. "With every improvement in "blood" a corre- sponding improvement in feeding and management must be made, or E'ature will surely thwart our plans by asserting her supremacy, and adapting the animal to the conditions in which it is placed. It seems to be the prevailing opinion that the cross of a large male upon the females of a small breed is not advisable, on account of the difficulty in parturi- tion which, it is presumed, would arise from the dis- proportionate size of the offspring. This belief must be founded on theoretical consid- erations only, as difficulties of the kind do not often occur in actual practice. After an extended experi- ence during the past ten years, in crossing rams of the Cotswold, Lincoln, and Southdown breeds on com- ^ Journal of the Royal Agricultural Society^ 1866, p. 329. For the advantages of crossing pure-bred and common swine, see Harris on "The Pig," p. 36. CROSS-BREEDING. 213 mon-grade merino ewes, I have failed to meet with a single instance of difficult labor arising from snch influence. In many instances, for the sake of experiment, the smallest ewes were selected for crossing with the largest rams, bnt in no case was the labor nnnsuallj severe or protracted. In establishing the " Charmoise " breed of sheep, M. Mahngie-]^onel tell ns that he frequently bred his mixed-blood ewes, that did not weigh more than twenty-five kilogrammes, to rams of the New Kent breed that weighed over one hundred kilogrammes, and that, in over two thousand cases of such contrast in the parents, he observed but a single " accident " from the disproportionate size of the lambs.' The size of the young animal at the time of birth is evidently determined by the dam, while its devel- opment after birth may be influenced by the inherited qualities of either parent. In the vicinity of large towns a peculiar system of cross-breeding is successfully practised in produc- ing early lambs for the market. Pure-bred rams of any of the improved English breeds may be used for this purj)Ose, but the South- downs, from their superior quality of flesh, are gener- ally preferred. As the rapid growth and development of the lambs is of the first importance, the ewes, which are selected from common-grade flocks, should be strong and healthy, although perhaps in low flesh, and, above all, good milkers. ' " Encyclopedic pratique de I'Agriculteur," vol. x., p. 595. 214 PRINCIPLES OF STOCK-BREEDING After the lambs are yeaned — about the first of March — the ewes should receive a liberal ration of grain and roots, to promote the secretion of milk, and, at the same time, improve their condition in flesh. At the age of two or three weeks the lambs will learn to eat meal and turnips, which should be placed in boxes to which they have ready access, in pens that their dams cannot enter. With good shelter, which must of course be pro- vided, and a system of high feeding, the lambs are ready for the market when from seven to ten weeks old, the highest prices being paid for the earliest lots. If not too late in the season, from four to five dol- lars per head can be obtained for good ones, while in- ferior or late lots are sold at much lower prices. After the lambs are sold, the ewes are fattened and sold for mutton, soon after shearing. "With the exception of the pure-bred ram, the en- tire flock is thus disposed of before the close of the year, the ewes frequently bringing one dollar per head more than their original cost.^ A new flock of ewes may then be procured, and the same method repeated. The essentials of success in this method of man- agement are, a high-bred ram that can impress upon his offspring the ability to mature early, high feeding to secure the greatest possible activity of this inherited tendency, and good shelter. * For details of Mr. Taylor's system of management, see The Culti- vator, 1862, pp. 77, 160, 174. CHAPTEE XL RELATIVE mFLUENCE OF PAEENTS. Theee are many theories in regard to the relative influence of parents upon their offspring, some of which, without sufficient reason, have been quite gen- erally accepted as established physiological truths. The Highland Agricultural Society of Scotland, in 1825, awarded prizes to four essays ^ on this subject, that were presented for competition. In the first volume of " Transactions " of the soci- ety, Mr. Boswell's essay is published in full, while ab- stracts only of the others are given. Mr. Christian claims that " any hypothesis which would assign a superiority, or set limits to the influ- ence of either sex in the product of generation, is un- sound and inadmissible." His essay is but briefly noticed, yet, so far as the influence of sex alone is concerned, his position has not been successfully con- troverted. The theory advanced by Mr. Boswell, ^ These essays were written by John Boswell, Rev, Henry Berry, Mr. Christian, and H. N. Dallas, in answer to the following question, which was presented by the society for discussior ; " Whether the breed of live-stock connected with agriculture be susceptible of the greatest improvement from the qualities conspicuous in the male, or from those conspicuous in the female parent ? " (" Transactions of the Highland Agricultural Society," vol. i., p. 11). 216 PRINCIPLES OF STOCK-BREEDING. that the male had the greatest influence in determin- ing the characters of the offspring, became quite popular, from the apparent indorsement it received by the society, as it was the only one of the prize essays that was published in full. As the cases cited by Mr. Boswell in proof of his theory are, almost without exception, susceptible of a different interpretation, the males used being more highly bred than the females, and therefore likely to be prepotent in the transmission of their quahties, his conclusions as to the superior influence of the male are not sustained by the evidence presented. More- over, we find on record a large number of as striking instances of the resemblance of the offspring to the female parent, which, in themselves, must be fatal to the theory. In the essay by Mr. Berry, a preponderance of the influence of either parent on account of sex is denied. The best-bred animal, however, is believed to have the greatest influence in determining the peculiarities of the offspring. Of the instances given by Mr. Berry to illustrate his position, the following are quoted on account of their bearing upon the theory of Mr. Bos- well, already noticed : " The writer," says Mr. Berry, " has been for some years in possession of an improved breed of pigs, which are chiefly of a sandy or brown color. His sows of this breed crossed with common boars almost invariably produce litters of pigs of their own color. At the present moment he has a litter of eleven pigs from a brown sow of the improved breed, by a black-and-white boar of the common breed. The young pigs possess all the characteristics of the RELATIVE INFLUENCE OF PARENTS. 217 dam, and are of precisely the same color. In litters of pigs got by the improved boars from country sows, the color of the improved race also predominates in a similar manner. . . . " The writer's brother was lately in possession of well-bred pigs, the most striking characteristic of which was a short, pricked ear. The produce of these with the large pendent-eared swine of ]N"orth Wales was invariably similar in the ear to the higher-bred animal, whether male or female." ^ The number of cases in which the offspring resembles the male are undoubtedly more numerous than the cases of resem- blance to the female, for the obvious reason that the males selected for breeding are, as a rule, more highly bred than the females with which they are coupled, and they have also more numerous offspring from which the cases of resemblance are selected. Those who overlook this fact, as is evidently the case with Mr. Boswell, fall into the error of attribut- ing the greater number of observed resemblances of offspring to the male parent to a predominating influ- ence of sex. The importance of securing males of the best quality, that from their superior breeding will be likely to be prepotent in the transmission of their characteristics, cannot be too strongly urged as one of the readiest means of improvement. " It is generally admitted as a fact proved, that in the ox, horse, and other domestic animals, the purer or less mixed the breed is, there is the greater proba- bility of its transmitting to the offspring the qualities * " Transactions of the Highland Agricultural Society," vol. i., p. 41. 218 PRINCIPLES OF STOCK-BREEDING. it possesses, whether these be good or bad. Economi- cal purposes have made the male in general the most important, simply because he serves for a considerable number of females. " The consequence of this has been that more at- tention has been paid to the blood or purity of race of the stallion, bull, ram, and boar, than to that of the females; and hence it may be the case that these males more frequently transmit their qualities to the offspring than do the inferior females with which they are often made to breed. But this circumstance can scarcely be adduced as a proof that the male, cceteris jparibus^ influences the offspring more than the female." ^ IsTotwithstanding the predominant influence of the " best-bred " parent is the rule, the intensity of other conditions, in many cases, interferes and produces un- expected variations. If high breeding has been prac- tised with reference to a single quality only, as, for instance, speed in the horse, and the qualities that give strength and constitution are neglected, the one- sided development of the animal may produce an un- stable ^condition of the organization that is not favor- able to uniformity in the transmission of the single character it is proposed to perpetuate. Stonehenge, in noticing such exceptions to the general rule, says : " My own belief in this matter, founded upon observations made during a long series of years, on the horse as well as the dog, is, that no rule can be laid down with any certainty. Much * Dr. Allen ThompsoB, article " Generation," in " Cyclopaedia of Anatomy and Physiology," vol. ii., p. 472. RELATIVE INFLUENCE OF PARENTS. 219 depends upon the comparative physical power and strength of constitution in each parent — even more, perhaps, than the composition of the blood. " There have been many instances of two brothers being used in the stud, both among horses and grey- hounds, in which one has almost invariably got his stock resembling himseK, in all particulars, not even excluding color, while the descendants of the other have rarely been recognizable as his. Thus among horses the Touchstones have been mostly brown or dark bay, and as a lot have shown a high form as race-horses; while the Launcelots have been of all colors, and have been below mediocrity on the turf.* Several examples of the same nature may be quoted from among greyhounds, such as Eanter, Gipsey Prince, and Gipsey Royal, three brothers whose stock was as different as possible, but the fact is so gener- ally recognized that it is not necessary to dwell upon it. " I^Tow, surely this difference in the power of trans- mitting the likeness of the sire, when the blood is ex- actly the same as it is observed to extend over large numbers, can only depend upon a variation in indi- vidual power. ]^ot only does this apply to the males, but the females also show the same difference." ^ After citing several other instances of such varia- tions, Stonehenge concludes by recommending breed- ers to be guided by his thirteenth axiom, which is as follows : " The purer or less mixed the breed, the more likely it is to be transmitted unaltered to the * Touchstone and Launcelot were full brothers. ^ " The Horse," by Stonehenge, p. 147. 220 PRINCIPLES OF STOCK-BREEDING. offspring. Hence, whidieyer parent is of the purest blood will be generally more represented in the off- spring; but, as the male is usually more carefully selected, and of purer blood than the female, it gen- erally follows that he exerts more influence than she does ; the reverse being the case when she is of more unmixed blood than the sire." ' Stonehenge is undoubtedly correct in the opinion that this axiom, on the whole, is the safest guide to the breeder in making his selection of animals with reference to the relative potency that may be expected in the parents. The cases that he cites of full broth- ers transmitting different characters to their offspring, may be readily explained in accordance with princi- ples that have already been presented, and it is, there- fore, unnecessary to assume that they form exceptions to the general rule that the best-bred parent has the greatest influence upon the apparent characteristics of the offspring. An examination of the pedigrees of the animals in question will show that several sub-families of the breed are represented in their ancestry, and we might reasonably expect that full brothers would inherit their leading characteristics from different branches of the family tree, which they in tm-n might trans- mit to their offspring. A long course of breeding in the same definite direction, or within the limits of the same family, would be required to secure uniformity in the domi- nant characters transmitted by animals closely related. * Loc. cit., p. 139. See also Journal of the Royal Agricultural So- ciety^ vol. xxii., p. 9, and vol. i., p. 24. PxELATrVE INFLUENCE OF PARENTS. 221 M. Girou believed that tlie relative a^e and vio-or of the parents determined their relative influence in moulding the characters of their offspring, and Stone- henge, in the paragraph above quoted, appears to be inclined to accept the theory as at least a plausible one. When all other conditions are equal, it may be true that the relative strength of constitution and physical vigor of the parents may, to some extent, determine their relative influence upon the dominant characters of their offspring, but there is no evidence that such influence is sufficiently intense to counteract or overcome, in all cases, the other causes of heredi- tary transmission. I have frequently observed in- stances of animals decidedly deficient in strength and vigor that were prepotent, even when coupled with those that were remarkable for their high constitu- tional development. It cannot be doubted, however, that in cases of marked immaturity, or of an impaired condition of the system from extreme old age, the powers of trans- mission are less strongly marked than they are in the meridian of health and development ; but these are extreme cases, that cannot be relied upon as indicating the normal laws of the function of reproduction. The excessive use of the male impairs his powers of procreation, and undoubtedly diminishes the po- tency with which he transmits his qualities.* When there is no marked prepotency on the part of either parent, the male offspring frequently resem- ble the father and the female resemble the mother.'' * " Massachusetts Agricultural Report," 1860, p. 172. * Colin's "Physiologie comparee," vol. ii,, p. 535; Journal of the 222 PRINCIPLES OF STOCK-BREEDING. This is often the case in the transmission of dis- ease, as has already been noticed in the chapter on hereditary diseases. Of two hundred and fourteen cases of consumption recorded by Lugol, one hundred and six were males and one hundred and eight fe- males ; of these, sixty-three males inherited the disease from their fathers and forty-three from their mothers : and sixty-one females inherited the disease from their mothers and forty-seven from their fathers. Phillips gives the history of two hundred and sixty-four cases of insanity, from which we learn that, of one hundred and seventeen males, sixty-four inherited the disease from their fathers and fifty-three from their mothers ; of one hundred and forty-seven females, eighty inherited the disease from their moth- ers and sixty-seven from their fathers.^ The peculiar horny excrescence on the skin of the porcupine-men (Lambert family), that was transmitted for several generations, was limited to the males of the family.'* The following case is reported by Dr. Stewart : " A single man aged twenty-four years, and the eldest son of a family consisting of two sons and two daughters, has well-iRSirked pityriasis versicolor (a disease of the skin) affecting his chest, back, and arms, and which was first observed when he was about fourteen years of age ; his brother, twenty years of age, now has Boi/al Agricultural Society, vol. xvi., pp. 21-35 ; Ribot on " Heredity," p. 2 ; Darwin's " Animals and Plants under Domestication," vol. ii., p. 93. 1 Journal of the Royal Agricultural Society, vol. xvi., pp. 21, 35. 2 British and Foreign Medico- Chirurgical Review, April, 1861, p. 246. RELATIVE INFLUENCE OF PARENTS. 223 it, thoiigli not to the same extent ; and his father, pa- ternal uncles, paternal grandfather, and seven male consins on the paternal side, have all been similarly affected ; the disease, strictly limited to the males, usu- ally appeared in all of them at puberty, and disap- peared about the age of forty or forty-five years ; while the females of the family, although not suffering from it themselves, have transmitted it to their male chil- dren. Atavism through the opposite sex occurred when females intervened to check its direct transmis- sion to males." ^ This disease of the skin is not, however, confined to males, and cases are recorded in which it has been hm- ited in a family to females. Mr. Sedgwick, in his re- marks on color-blindness, says : " An analysis of upward of two hundred cases shows that the proportion of males affected is nine-tenths of the whole. But as I had occasion to state with reference to the same point in ichthyosis, this apparent preference for the male sex is not due to any peculiar inaptitude in the female sex to the defect ; for when it has primarily affected the latter, its sexual limitation is complete, as in the interesting case published by Mr. Cunier, where the defect occurred in thirteen individuals belonging to five generations of one family, all of whom were fe- males." ^ Ribot remarks that " the resemblance between par- ents and children may undergo such metamorphoses as shall cause the child to resemble at one time the * British and Foreign Medico- Chirurgical Review, A.^v\\ 1863, p. 449. » Ibid., April, 1861, p. 253 ; " Cyclopaedia of Anatomy and Physiol- ogy," vol. iv., p. 1454. 224 PRINCIPLES OF STOCK-BREEDING. father, and at another the mother. Girou de Buza- reingues, in his work ' De la Generation,' containing some cnrions facts observed by him, tells us that he knew two brothers who in early life resembled their mother, while the sister resembled the father. " These resemblances were such as to strike all who saw them. ' But now,' says he, ' and ever since their youth, the two boys resemble the father, while the daughter has ceased to be like him.' " ' Cases not unfrequently occur in which the disease or defect is limited to one sex and transmitted by the other, as in the case of ichthyosis above noticed. " In the following cases of sebaceous tumors of the scalp, which occurred in the practice of Dr. Henry Stewart, and which were hereditarily limited to the female sex, in the first case for ten and in the second case for ^ve generations, it will be observed that in the first case limitation by age as well as by sex oc- curred, and also that some of the females derived the inheritance from their paternal grandmother by atavic descent, which affords an additional proof of the influ- ence of sex, for, except when a male thus intervened to arrest the appearance of the disease, the inheritance was direct from parent to child. . . . " The wife of a painter, aged fifty-four years, has thirty-three sebaceous tumors of the scalp, none of which are larger than a walnut ; but thirteen years ago nine sebaceous tumors, varying in size from a nutmeg to a small orange, were excised by the late Mr. Mor- ton, with considerable relief to the severe headaches she had previously suffered from ; her daughter and ' Ribot on "Heredity," p. 3. RELATIVE INFLUENCE OF PARENTS. 225 her granddaughter are both affected by them, her sons are perfectly free; her brothers' daughters are troubled with them, as well as several female cousins of different degrees of relationship ; her mother, grandmother and female relations backward for seven generations, were similarly affected; no female who had attained her tenth year of age was without them, while none of the males in the family had ever had them. . . . " A single woman aged thirty years, the only child of her parents, and suffering from phthisis in the sec- ond stage, which she has inherited from her mother's family, has ten sebaceous tumors on the scalp, varying in size from a nutmeg to a pea, and which were first observed when she was about fifteen years of age ; these tumors have been common to the females of her moth- er's family — her mother, maternal grandmother, ma- ternal great-grandmother, and maternal great-great- grandmother, all had them, and so likewise have sev- eral female cousins on the mother's side of the first and second degrees of relationship ; all the females, but none of the males in the family have suffered from them." ' Mr. Sedgwick also reports a case of warts on the hands of the mother during childhood (they disap- peared after puberty), that were transmitted to her three daughters, while her two sons were exempt. " In the report of hereditary malformation of the hands, affecting ten generations of the same family, it is stated that 'it was the women only who had the ^ British and Foreign Medico- Chirurgical Review^ April, 1863, pp. 450, 451. 226 PRINCIPLES OF STOCK-BREEDING. misfortune of entailing the defect on tlieir off- spring.' " ^ A case of cleft iris (wliicli is the analogue of hare- lip) is recorded by Mr. Sedgwick, who sums up the details as follows : " The chief points of interest in the case are — 1. The transmission of the defect with- out its being shared in by the mother ; 2. That, while two of her three sons had the defect, her three daugh- ters were free from it ; and, lastly, that the maternal grandfather, the maternal grand-uncle, the maternal uncle, and the son of this last named, all shared in the defect, which shows that the inheritance in this case extended to at least four generations." ^ According to Mr. Wilde, " In a family of thirteen, in the county of Sligo, mute twins occurred twice, be- ing the seventh and eighth births : in the former both children were mute females ; in the latter, a male and female, the boy not mute. Of the entire thirteen births in that family, five were males, none of whom presented any defect; and eight were females, of whom seven were deaf and dumb ; the order of the birth of the mutes being the third, fourth, fifth, eighth, ninth, and eleventh." The same author states that " the proportion of sexes of the deaf and dumb in England and Wales, where one in 1,738 of the inhabitants was affected, is 100 males to 82.9 fe- males ; in Scotland, where one in 1,340 of the inhab- ^ Edinhurgh Medical and Surgical Journal, vol. iv., p. 252, ISOS, as quoted in British and Foreign Medico- Cliirurgical Review, J^^ljj 1S61, p. 148, note. ' British and Foreign Medico-Chirurgical Review^ April, 1861, p. 249. RELATIVE INFLUENCE OF PARENTS. 227 itants was affected, is 100 males to 80.0 females ; in Ireland, where one in 1,380 of the inhabitants was affected, is 100 males to Y4.5 females ; in Prussia, where one in 1,360 of the inhabitants was affected, is 100 males to 78.0 females — the last statement being taken from M. Bandin's statistics." * Mr. Sedgwick reports a case of chronic rhenmatic gout, which made its appearance "gradually, in a woman at the age of thirty years, and the joints of whose hands are now, at the age of forty-three years, much crippled and deformed ; her mother, who died at the age of forty-six years, suffered greatly from chronic rheumatic gout, which had commenced thir- teen years previously, and which had thoroughly crippled and deformed the joints of both hands; there were three brothers and four sisters, the eldest of whom was a brother aged forty-five years, all of whom have been free from any similar affection ; and in another case which is at present under my obser- vation, in which a girl, aged eighteen years, has the hands and feet dreadfully crippled by the same affec- tion, which began at the age of fourteen years ; her mother, maternal aunt, and maternal grandmother, have all suffered in the same way, while the males of the family have been exempt." " Mr. Sedgwick reports the following case, which occurred in his own practice : " Mrs. A , under the age of forty years, and the mother of seven children, has not had for many ^ From " Report of Census in Ireland," as quoted by Mr. Sedgwick in British and Foreign Medico-Cliirurgical JRevieto, July, 1861, p. 141. 2 British and Foreign Medico- Chirurgical Bevi CYCLOPEDIA OF APPLIED MECHAN- ICS. A Dictionary of Mechanical Engineering and the Mechan- ical Arts. Illustrated by 5,000 Engravings. Edited by Park Benjamin, Ph.D. 2 vols., 8vo. Sheep, $15.00; half morocco, $17.00. Appletons' Cyclopjsdia of Applied Mechanics of 1879 is a new work, and not a revision of the former Dictionary of Mechanics of 1850. It presents the best and latest American practice in the mechanical arts, and compares the same with that of other nations. It also exhibits the extent to which American invention and discovery have contributed to the world's progress during the last quarter century. The contributors include many of the most eminent American mechanical experts and engineers. Several of their contributions contain the results of original research and thought never before published. Their efforts have in all cases tended to simplify the subjects treated, to avoid technicalities, and so to render all that is presented easily understood by the general reader as well as by the mechanical student. Examples are appended to all rules, explanations to all tables, and in such matters as the uses of tools and management of machines the instructions are unusually minute and accurate. II. Arnott, Neil. Elements of Physics ; or, Natural Philosophy. Sev- enth edition. 12mo. Cloth, $3.00. III. BonrnCy John. A Catechism of the Steam-Engine. New revised edition, with Illustrations. 12mo. Cloth, $1.75. IV. Bourne, John. Hand-Book of the Steam-Engine. Constituting a Key to the " Catechism of the Steam-Engine." Illustrated vrith 67 Woodcuts. 12mo. Cloth, $1.75. " No man in the country, perhaps, possessed better requirements for writing a comprehensive scientific and practical work on stock-breeding than Professor Miles. His studies as a physician, his observations as a naturalist, his experi- ence as a breeder of stock, his studies while Professor of Agriculture, his knowl- edge acquired in travel, all helped qualify him for the work he undertook. As a compendium of what is known of stock-breeding, his book is doubtlessly supe- rior to any work of the size ever written. It is deserving of being adopted as a text-book in every agricultural college, and is worthy of a place in the library of every stock-breeder in the couatTj. "—Chicago Times. "Millions of dollars in this country alone are invested in domestic animals; and many thousands of men are interested in breeding them ; and yet, as a general thing, each man has learned what he knows of the matter by tedious, and often expensive, personal experience. A volume like the one before us, if faith- fully read, will aid him immensely in his business."— Foow«ocA:e< Daily Patriot. " That the bulk of our farmers stand greatly in need of some such help as Professor Miles tenders, no one can doubt. We have examined this work care- fully, and believe it to be the most intelligible and systematic book on the sub- ject within the reach of the American farmer."— Utica Daily Observer. " It gives, in a very lucid and original manner, the experience and practice of the most successful breeders."— jBoston Courier. "It is not a learned and dry dissertation of the subject, but lightly and admirably written, with not a dull or uninteresting page in the whole four hun- dred."— PAitoc?e?i?Aia Item. " To stock-breeders it is indispensable."— Sar^/orcf Courant. " While the book is thoroughly scientific, it is simple enough to be of practi- cal value to the farmer and stock-breeder of limited resources and investigation." " There is not a farmer or a herdsman in all the Southwest who is not inter- ested in this subject, and who can not from a reading of this work leam how to double the weight of his beeves or triple the yield of his dairy cattle."— yS"^. Louis Times-Journal. " In a direct and lucid way. Dr. Miles has collated the facts and discussed the principles bearing upon his subject, more carefully than is done in any other work accessible to the general reader, and down to a later period than in any other whatever within our knowledge. Throughout the author shows great familiarity with his subject, the fruit of extended and judicious reading and of personal observation and experiment."— J.»any Cultivator and Country Gentle- man. " Dr. Miles's work is called for. Though largely philosophical and scientific, it is also so exact and and comprehensive that it must benefit all who read intel- ligently and use their information. 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