U. S. DEPARTMENT OE AGRICULTURE. BUREAU OF PLANT INDUSTRY— BULLETIN NO. 58. B. T. GALLOWAY, Cliirf „f Hurcau. T H K VITALITY AND (.RUMINATION OF SEEDS. J. W. T. DIJVEL, Assistant in the Seed Tvap.oratory. BOTANICAL INVESTIGATIONS AND EXPERIMENTS. ] M M WASHINGTON: GOVERNMENT PRINTING OFFICE. 1 9 4 . ttoW^hMll Glass. Book. /v U. S. DEPARTMENT OE ACRIClT/rURE. BUREAU OF PLANT INDUSTRY— BULLETIN NO. 58. ]'.. T. (iAI,l,i)\V.\ V, clii,/ (if r.iirinn. the; 6^^f VITALITY AND TERMINATION OF SEEDS. y ■ T J.MV/TM)IIVEL, Assistant in iiie Seed Lauoiiatoky, BOTANICAL INVESTIGATIONS AND EXPERIMENTS. Issued May 2S, 1004. WASHINGTON: GOVERNMENT PRINTING OFFICE. BUREAU OF PLANT INDTSTRY. Bkvkkly T. Galloway, Clilrf. J. E. Rockwell, Editor. BOTANICAL INVESTK^ATIONS AND EXPERIMENTS. SCIEM'IFK' S'lAVK. Frederick V. C'oville, Hdlmiist. (). F. Cook, Boldiiisl in, (1itirt/c of Investigations in Tmjncnl Ai/rirulturc. Rodney II. True, I'lii/sioloj/ist, Drug and Medicinal Plant Inrcstigations. Lyster II. Dewey, Botanist in Oiarge of Investigations of Filx-r Plants. Edgar Brown, Botanist in Charge of Seed Lahoratin'ii. Carl S. Scofield, Botanist in Charge of Grai)i (,'rade Inrrslig<(tio7is. G. N. Collins, Assistant Botanist, Tropical Agriculture. A. v. Crawford, Pharmacologist, Poisonous Plant InrcKtigations. William E. Safford, Assistant Curator, ■Tropicy J. W. T. Duvel, Assistant in the Seed Laboratory, and has been submitted by the Botanist with a view to pul)lication. Respectfully, B. T. Gallow^av, Cliicf of Bureau. Hon. James Wilson, Sccrctarij of Agriculture. P R E FACE Bocauso of variation in tlu^ amount and ([uality of oach year's crop it is froiiuontly necessary for seedsmen to carry over lar^e ([uantities of seeds from one year to anotlier. Such seeds often lose their al)ility to germinate, and either are a h)ss to the seedsman or, if they arc marlvcted, cause still more serious losses to thos(^ who plant them. Since IS'J'J Mr. Duvel has l)een ongag-ed in a oeneral investigation of the causes afi'ecting the vitality of seeds, with special reference to the conditions under which tliey nvo stored conunercially. This investiga- tion was l)egun in IS'.I!) under the Dexter M. Ferry Botanical P\dlow- ship at the University of Michigan, and since Septeml)er 1, 11)02, it has heen contiiui(>d by the ITnited States I)(^pai-tment of Agriculture. An account of the whole study is presented herewith. The general method pursued has been to store seeds experimentally under all sorts of conditions, and afterward to ascertain the exact ptn-- centage of gin-mination. It is now possilde to speak with precision of the extent of damage causcnl by careless methods of storage, to expi'ess in actual hgures the greater liability of seeds to loss of vitality under the warm humid conditions (^xisting in the South Atlantic and Gulf States than under colder and drier conditions, and to demonstrate the utility of storing seeds, when they must V)e kept in a hunnd climate, in moisture-proof packages. A further iu\'estigation, i. e., of the extent to which \italitv may be preserved by means of conuuercial cold stor- age, is now in progress. Frkdkkk;k V. Coviixe, Office of Botanical Tnvestications and Experiments, WasJi!)i^ lUO-]. 5 conti^:nts. Page. Iiitrdductinn 9 Matei'ials and inctli() 2. Ai)]>aratus used to determine tlie effect of moisture and temi>erature on tlie vitality nf seeds nat in conununicatinn with fret' air oO B. p. T.-94. B. I. K.- THE \1TA1JTY AND GERMINATION OF SEEDS. INTRODUCTION. ]t has long- Ijcen known tliat the conditions nndor which plants are grow n and the dog-ree of niaturit}' at the tinu^ of harvesting are fac- tors which play an important part in the life of seeds. But, granting that seeds are of strong vitality at the time of harvesting, there remain to ])e considered the methods of gathering and curing, the water content of the seed at the time of storing, the methods of stor- age, the humidity and temperatui'e of the surrounding atmosphere, the composition of the seed, the nature of the seed coats, activities within the cells, and munerous other factors which play important parts in the life of the seed. The conditions necessary for the successful germination of a seed of good \itality and the chemical transformations accompanying these carl}' stages of development have received considerable attention from numerous investigators. These changes and conditions are fairly well understood for many of our common seeds. However, several impor- tant facts still remain unexplainiHl, and our knowledge will not be complete until each and every species has Ijeen carefully studied. On the other hand, the conditions influencing the vitality of seeds as commercially handled are but little understood and hav(^ })een almost wholl}' neglected in research work. Likewise, but little attention has been given to the complex chemical and physical changes which take place in mature seed dui'ing the slow process of devitalization. It was in order to determine some of these factors that the work described in these pages was begun, and the results are thus of consideral)le practi- cal value as well as of scientitic importance. The present paper treats chiefly of the conditions influencing the vitality and germination of seeds when sul)jected to such methods of treatnuMit as are generally met with in the ordinary handling of seed. Particular attention has been given to the effect of climate, moisture, and temperature on vitality, supplemented with a discussion of the changes taking place in mature seeds, especially the respiratory activities and the part pla3'ed l)y euzj^mes. 9 10 THE VITALITY AND OEKMINATION OF SEEDS. Tho results of the ;il)ove experiments have sug-gested ioiproved niethods of stofing and shipping seeds so as to prolong their vitality and also to secure the production of more vigorous seedlings. The work for the present i)aper was ])egun in lS9i) at the University of Michigan and was continued for three consecutive years while the writer held the Dexter M. P^rry Botanical Fellowship in that institu- tion. During this time the investigation was under the direction of Prof. y. M. Spalding, Ph.D.. and Dr. F. C. Newcoml^e, who showed great interest in it and gave Aaluablc suggestions as the work pro- gressed, at the same time placing the facilities of the laboratory and of the lil)rary at the disposal of the writer. Since September 1, 1902, the work has been continued in the Seed Laboratory of the U. S, Department of Agriculture. Valuable assistance in storing seeds was rendered by Prof. C W. Burkett, at Durham, N. H. ; Mr. E. E. Smith, Wagoner, Ind. T. ; Prof. W. R. Dodson, Baton Rouge, La.; Prof. F. S. Earle, Auburn, Ala. ; Zimmer l^rothers. Mobile, Ala.; Prof. H. H. Hume, Lake City, Fla., and Prof. Charles B. Scott, San Juan, Porto Rico. Materials and methods. SEEDS. For these experiments thirteen diU'erent samples of seeds were used, being so selected as to include representatives of ten dift'erent families and twelve genera and species, as follows: Poaceix — ZeCL tiiays^ sweet corn (two samples). Liliaceae — Allium, cepa L., onion. Brassicaeex — Br the radish (Early Scarlet Turnip-Hooted), carrot (Chantenay), pansy (mixed), and Phlox druiii'incnidu (mixed) were grown in France. The seed was all of the harvest of 1890 and was received at the l)otanical laboratory of the University of Michigan on January 27, 1900. On January 30, 1900, germination tests were made, showing the vitality of the seeds to be as follows: Vitality of seeds tested January 30, I'jOO. Kind of seed. Percent- age of germina- tion. Kind of seed. Percent- age of germina- tion. Bean 100 Pansy ti'.l. 5 93 Pea '.)7 83.5 94 88 87.5 98 Phlox 7.S SI Radish Tomato . . . 98 Watermelon 99 Onion GERMINATION TESTS AND ArPAHATUS. In the preliminary work several methods of testing were tried, but as none proved as serviceable as the ''Geneva tester," this apparatus was adopted for all subsequent tests as recorded in the following- pages. The detailed construction of this tester need not be descril)ed, for it is simple and quite familiar to all. However, some nioditications were made in the preparation of the apparatus, and some precautions taken in the manipulation, which have proved to be of much value. The brass wires originall}' and ordinaril}'^ used to support the folds of cloth were replaced by glass rods of (I to T mm. diameter. Rods of this si>5e are mucli heavier than is necessary to support the folds of cloth, but the chief advantage in having rods of large diameter is that in case of the germination of large seeds the folds can be drawn near together at the top and still have sufficient space within the fold for the seeds. On the other hand, in the germination of small seeds that require considerable^ ((uantities of air, the folds can be closed at the top ])}' bringing the rods together, thus insuring more uniform condi- tions throughout the fold and at the same time leaving sutlicient space above the seeds for an a])undant supply of air. The chief advantage in substituting glass rods for brass wires is in removing the possible source of injur}- resulting from the poisonous action of the dissolved copper. Another error f requentl}', if not alwa^^s, made in using such a tester is in allowing the ends of the cloths, or sometimes the bottoms of the 12 THE VITALITY AND GERMINATION OF SEEDS. folds, to dip into water in the pan. This should never be permitted, for in that wa}" seeds are kept too moist, especially near the ends of the folds. Likewise such methods o-ive an opportunity for the trans- mission of dissolved copper and a resulting;- injury to the seeds. For this same reason the strips of cloth should be made sufficiently narrow not to come into contact with the sides of the pan. Much better results are ol)tained if the seeds, before being placed in the germinator, are soaked in water for several hours, the length of time depending on the power of absorption of the seeds. In these experiments the seeds were always soaked in distilled water for twelve or fifteen hours before transferring them to the germinator. This preliminary soaking gives a more speedy germination, which is always advantageous, especially in making comparative germination tests. In order to supply the requisite amount of moisture for subsequent growth, the cloths were first uniformly and completely wet with dis- tilled water; moreover nuich care was taken to see that there was only a very small quantit}^ of water in the bottom of the pan. In case of seeds that germinate readily, such as cabbage, lettuce, and onion, it is necessary that all surface water be removed from the bottom of the germinator if good results are desired. The pan then being covered with a glass plate, it is seldom necessary to increase the amount of moisture, for seeds when once soaked need only to be kept slightly moist and not wet, as must necessarily^ be true if the ends of the cloths or l)ottoms of the folds dip into the water. After soaking, the water in the seeds and cloths is ample for the completion of most germina- tion tests. However, in an occasional test the seeds may become slightly dry, which happens when the cover is kept off the pan for a considerable time while counting germinated seeds. In such cases the remedy is to pour a small quantity of water in the bottom of the pan, or in extreme cases to moisten the folds with a fine spray. If the above modifications be adopted and the necessary" precautions taken, many of the objections frequently made to the Geneva tester will be removed and the difficulties will be overcome; at least it is a most excellent method of testing seeds where comparative results are especially desired. It must also be borne in mind that the Canton flan- nel (which is generally used in making the pockets) should ahva3\s be of the best grade and should never be used a second time without l)eing thoroughly cleaned and sterilized. In selecting samples for germination the impurities and the imma- ture seeds were first removed. The samples for test were then made up of the remaining large and small seed. For the most part 200 seeds were taken for a test, hut with the larger seeds — corn, pea, bean, and watermelon — 100 seeds were usually used. In all cases where any irregularity was apparent, tests were repeated. The controls are based on the results of several duplicate tests. EFFECT OF CLIMATIC CONDITIONS. 13 All germination tests were made in a dark room where the temper- ature could be comparative!}' well regulated and was maintained nearly constant throuohout most tests. Germiniited seeds were removed dai 1 y during early stages of the tests and a com]>lete record of the munher germinating each day was kept. Tliis is of value in seed testing, because the germinative energy of a seed tells nuich as to its vitality. If seeds have a high vitality, the germinative energy will l)e very strong, i. e., germination will take place rapidly, giving rise to strong and vigorous seedlings; )>ut if the seeds are of very low vitality, there will l)e a corresponding retardation in germination, giving rise to weak seedlings, i. e., showing a low germinative energy. In most cases throughout this work only the tinal percentages of germination are tabulated. EFFECT OF CLIMATIC CONDITIONS ON THE VITALITY OF SEEDS. It has long since been known that seeds under ordinary conditions lose their power of germination after the lapse of a few years, or in some cases within a few weeks or months. Many investigators have also learned that the rapidity with which seeds lose their vitality, when stored under ordinary conditions, ^'aries greatly with the; section of the country in which such seeds are kept. This loss in vitality is espe- cially marked in the case of seeds stored in places of relatively high humidit}'. The rapid deterioration of seeds in localities having a humid atmosphere has become a source of much embarrassment to seedsmen, for they have experienced many difficulties in shipping seed to such places. This is especially marked in the case of seeds sent to growers or dealers in the vicinity of the Gulf of Mexico. Gardeners and planters in that part of the United States are continually com- plaining about the nonvial)h', seeds sent out l)v seedsmen. Some grow- ers have learned how to guard against this difficulty to a certain extent. Zimmer Brothers, of Mobile, Ala., wrote, on Feljruary 2S, 11)00, con- cerning this matter, as follows: During thirty years' experieni'e in market gardening, we have iearneil tliat .seeds of many hardy plants will not keep in our climate, and when ordering we so time our order that we can plant the seeds as soon as received. If such be impossible, we are very careful to keep the original 2>aekage unopened until conditions are favorable for planting. If we find it necessary to keep seeds of hardy plants for some months, we put them uj) on arrival in dry bottles, put on toj) a bit of cotton saturated with chloroform and cork tightly. AVe have kept, in that way, cauliflower seed satisfac- torily for twelve months. At the shore seeds keej) very badly; one-half mile back they do much better. As a rule seeds of tender ]>lants give but little trouble. As far as has ])een ascertained, no definite experiments have been made with these points in view, and especially with the idea of deter- mining the cause or causes of this deterioration of \ ital energy. In order to obtain reliable data on these points, a series of experiments was undertaken in Fe))ruary, 1900, to determine how seeds are atiected 14 THE VITALITY AND GERMINATION OF SEEDS. when cli(stri))uted to dirterent parts of the United Stute.s iindsu]>niitted to the free influence of various climates. Likewise at the vai'ious points where tests were made the seeds wore subjected to diflerent treatments. The phices selected for these tests were San Juan, P. R., LakeCit}", Fla. , Mobile, Ala. , Auburn, Ala. , Baton llouge, La. , Wagoner, Ind. T. , Duj'ham, N. IL, and Ann Arbor, Mich. A sample of each species of seed was put up separateh' in double manila coin envelopes and in closely corked bottles. Dujilicate sets of each series w^ere then subjected at each of the above-named places to the following' conditions: Trade c(m(1!tt(ms.^Con^\i\oi\ii similar to those in which seeds are kept when offered for sale by retail dealers, the seed being- more or less exposed to meteorological changes and su])jected to natural varia- tions in temperature and humidit3^ For the most part the seeds were in rooms that were never heated. Dry rooms. — Rooms in the interior of buildings which were artifi- cially heated during cold weather, and where the quantity of moisture was relatively small and the temperature comparativel}^ constant. Bamments. — Rooms where the temperature was comparativel}^ low^ and uniform, and the relative humidity of the surrounding air was much higher than in "trade conditions" and "dr}^ rooms."" These conditions varied in the different places at which tests were made, and a more detailed description will be given when the results of the germination tests are discussed. For the first part of this paper, treating of the influence of climate on vitality, none of the seeds need to be considered save those pre- pared in paper packages and kept under trade conditions, these coming more nearly under the direct action of the surrounding atmosphere. A sample of each kind of seed was put up in a manila (No. 2) coin envelope, and each of these packages was then inserted in a second (No. 3) coin envelope. Duplicate samples of ever}^ kind of seed were sent to the A^arious testing places, where they Avere su])jected to trade conditions. At San Juan the packages of seeds were kept in an open room, being siil)jected to the full action of the atmosphere but pro- tected from the direct rays of the sun and from rain. At Lake City the packages were kept in a one-story frame building which was not artificially heated and the doors of which were open the greater portion of the time. At Mobile the packages of seeds were stored in a comparativel}" open attic of a private dwelling. At Auburn the seeds were stored in a greenhouse office, with the doors frequently standing open. At Baton Rouge the packages were kept on a shelf in a grocery store, the doors of which were closed only during the night. At Wagoner the conditions were very similar to those of Baton Rouge, save that the packages of seeds were kept in a drug store. At Dur- ham the seeds were kept over a door at the entrance of one of the KFFKCT OK CLIMATIC CONDITIONS. 15 colleg'e l)iiil(liii_ii;'s. 'Plii.s door opens into :i hall wliicli coinnuniicatcs witli the ottices, cheniiciil I:il)orat()iT, and the basemeiit. At Ann Ar])or the seeds were stored in the Itotaiiieal laboratory, with slightlj varj'ino- conditions, they bein^- near a window whicli was fre([uently open durinio" the suminer. and at irre<^ular intei'\als during- the early part of the sunnner the packages were placed in the window so as to receive the diiect rays of the sun. The seinls stored at Ann Ai'bor served partially as conti'ols for those sent to tlu^ ^•arious otluM' places, and, in addition to the last-named series, seeds from tht^ original packag'es, as received from I). M. Feriy c'v: Co.. wei'c kept in a dry and comparatively^ cool closet on the fourth floor of the botanical lab- oratory. These seeds served as checks for tlu^, complete set of exper- iments, and arc designated throughout this paper as "C'ontrol.'' The samples were sent out to the al)Ove-ir.im(ul places in February, 1900. The first conn)lcte set was returned in fFune, or early July, of that year. The second complete set was allowed to remain throughout the entire sunnner, and was returned in October and eaily November of the same year. The average time of treatment for the two series of experiments was 12S and 251 days respectively. ANhen the seeds were returned, germination tests were made as soon as possible. The length of time that the seeds were in the various places and the vitality as shown by the gei'mination tests are given in Tables I and 11. In both tables the colunms from left to right, })eginning with Mo))iIe, Ala., are in the order of the degree to which the seeds were injured. Tahle I. — l^jffect of rliiiidli' on luto/ili/, <(.s shoii'ii hij prrceiihtf/c of ijennliiatioii — ;///-.s7 test. Kind of seed. Corn, sweet, "A"... Corn, sweet, "B" .. Onion Cabbage Radish Carrot Pea Bean Pansy Plilox drumniondii. Tomato Watermelon Lettuce Average of all seeds Con- trol. Mobile, Ala., Feb. 17 to .Iulv7. lio davs. San Juan, P. R., Feb. 9 to rune 20. days. 90. 72.0 S4. f, .S2. (i 1. 71. f) 91.0 100.0 •20. 23. r, 94.0 90.0 79.0 7.=). 12 Baton Rouge, La., Feb. 17 to JunelS. 121 days. 96. 80. 90. 8S. 77. 71. 94. 90. 2.S. 47. 91. 100. Wagon- er, Ind.T.. Feb. 17 to .Iune23. 120 days. Lake City, Fla., Feb. 9 to JunelS. 129 davs. 96.0 70.0 93. .'■) .S3. T) 77. f) SI . f) 9S. 90. 4S. .'•) 50. r, 90. 5 98. 7S.0 82. 12 94.0 80. 95. 89. 5 79. 90.0 98. 41.5 41.5 94.0 98. 87. .S3. 00 Dur- ham, N. H., Feb. 17 to Julv 14. 147 lavs. 100. 89. 3 90. 5 93. SO. 78.0 98. 100. .55. 5 07. 94. 5 98.0 82. Au- l)urn, Ala., Feb. 17 to May 30. 102 davs. 90. 8,S.0 9(!. 91 . 75. 5 Si. 5 93. 3 9S. 57. 5 01. 5 95.0 94.0' SO. 5 Ann. Arbor, Mich. 100.0 92. 9.5.0 90. .82. 5 70. 90. 98. 53. 5 07.0 89.0 100.0 82.0 85. 57 .85. 70 ,80. 23 From Table I it will be seen that the loss of vitalit}' in the case of seeds stored at Mobile was much greater than in those stored at any of the other places. The greatest loss in the samples tested was in the 16 THE VITALITY AND CIEEMINATION OF SEEDS. phlox, where the <^ernun!itioii was only 0.5 per cent, or a Uj.ss in vitality of 1)9.3 per cent as compared with the control. These results were closelj' followed by a lo^s in vitality of 1>.5.1> and 92. T per cent for the pansy and onion seed, respectively. The percentages of germination in the other cases, except the "B"" .sweet corn, pea, and bean, were sufficient to have produced a fair stand, i. e., if we consider that far too -many seeds are usually sown. But a decrease in the percentagH; of germination means seeds of a low germinative energy. Even though the tinal percentage of germination be up to standard, the retardation may l)e of vital importance. A very good example of the retardation in germination is shown in the tests of the watermelon seeds. In the control sample 94 per cent of the seed germinated in 472^ hours, while the seed returned from Mobile showed, during the same time, a germination of only 13 percent; yet the difference in the hnal germination w'as only 0.3 per cent in favor of the control. Like- wise the seed returned from San Juan germinated only 30 per cent in 47^ hours, the final germination being 90 per cent or only 2.3 per cent lower than the control. Many similar cases might be mentioned in which the final per- centages of germination, as shown by the first set of tests given in Table I, represent a loss such as might be justly considered well within the limits of normal variation. However, that all of the samples of seed were injured as a result of the unfavorable climatic conditions is shown in the second set of tests set forth in Tal)le JI. In the latter case the seeds remained in the \arious places nearly twice as long as those used for the first test. Table II. — Effect of climate on vitality an t^howii hi/ 2>ercentage of (jerrn'mation — second test. Kind uf seed. Con- trol. Mobile, Ala., Feb. 17 to Nov. 6. 262 days. Baton Rouge, La., Feb. 17 to Get. 22. 247 days. Dur- ham, N.H., Feb. 17 to Oct. 26. 251 days. Au- bTirn, Ala., Feb. 17 to Nov. 19. 275 days. Lake CMtv, Fhi., Feb. 9 to Oct. 1. 234 days. Wag- oner, Ind. T., Feb. 17 to Oct. 13. 238 days. San Juan, P.R., Feb. 9 lo .Tune 20. 129 days. Ann Arbor, Mich. Corn, sweet, "A" Corn, sweet, " B " Onion 91. 5 ,S,H. 5 97. 92. 4 7s. s ,S2. 9.'). 7 9.H. 7 r.3. 53. 9 97. 5 99.0 92.3 20.0 12.0 0.0 17.0 51.0 8. 5 44.0 0.0 0.0 0.0 79. 5 (-.4. 20.0 88. 51. 2 0.5 25. 80.0 GO.O 0.0 0.0 90.0 92. 84. 5 96. 82. 0.0 12.0 59. 5 2.0 91.0 78. 0.0 0.5 87.0 82.0 88. 5 88. 62. 12.0 61.5 63.0 36.0 97.9 56.0 2.0 1.0 94. 86.0 86.0 92. 77.0 16.5 63. 5 58. 5 43. 5 86. 5 84.0 1.5 2.5 94.0 92.0 85.0 90. 78.0 21.5 70. 5 (iO. 5 49. 80.0 82. 7.5 5.5 94.0 94. 82. 92. 78.0 50. 76.2 62. 48. 5 98.0 96.0 6.5 11.5 96. 5 88. 83. 5 98.0 80.0 97.5 Cabbage 91.0 77. 5 86.0 Tea 98. 100.0 46.5 Phlox dnimmondii Tomato 40.0 98.0 96.0 Lettuee 92. 5 Average of all seeds . 8(5. 77 24. 31 50.86 52. 42 57. 34 61.27 62.11 68.21 84.. 58 KFFKCT OK PLIMATIC CONDITIONS. 17 Im'cii thouyli tlu' eoluiniis ill ])otli Tu])los I and II uro !iiT:iiii;<'d in t!ic> order of the loss in vitality as shown )>y tiu^ a\(M'a of injury did not remain tliesanie tlirouo-hoiit the ex])eriinent. This is pi'olnibl}^ best explained ])y a variation in the climatic inlluences. It is evident that in some of the places where seeds were stored the eti'ects were more deleterious duriuL;- the time between the tirst and second tests than they were during the lirst period of stora^'c of It^S days. The results given in Table II arc of the greater value in showing the r(dative merits of the dilferent localities as ])laces for storing seeds, extending aA the}' do over a longer period of time. As a result of the second series of tests itw'as found that the average percentage of germination of all of the samples of seed that were stored in trade conditions at Mobile for 202 days was oidy 24:. HI per ccMit. This is equivalent to a loss in vitality^ of Tl.'.KS per cent as compai'ed with the average percentage of germination of the control samples, the average germination of the controls being S(). 77 per cent. The pansy, phlox, onion, and beans stored at Mobile wholly lost their power of germination. The tomato seed, which proved to ])e the most resistant to unfavorable conditions, gave a germination of 7t).5 per cent, or a loss in vitality of 18.46 per cent, as compared with the control sample, which germinated 97.5 per ciMit. The degree of deterionition in the seeds stored at the other places was much less marked than for those stored at Mobil(\ Th(» loss in vitality was only 4L.o!> per cent in the s(H'ds retui'ned from Baton llouge. The results from the seeds which were stored at Durham, Aui)urn, Lake C-ity, Wagoner, and San fJuaii diti'ered 1)ut little from those from Baton liouge. The ivlative losses in vitality are in the order given. The seeds k('i)t in the packages which were stored inider trad(- conditions in the lal)()i'at()ry at the CJniversity of Michigan showed a loss in a itality of only 2..'>2 per cent as compared with the control, the seeds of which wen^ stored in a cool, dry closet on the fourth Hoor of the botanical laboratory. Ordinarily a loss of 2.52 per c(Mit would 1)e considered as a normal \ariation due to sampling and testing, and such was ])i'()bai»ly true in these two sets, with the exception of the greater deterioration of the phlox, pansy, and '"B" sweet corn, wdiich were undoubtedly injured by the unfa- vorable trade conditions, as repeated tests have shown. From Table II it will also be seen that the ^'A'' sweet corn, peas, tomato, and watermelon, with the exception of tiiose returned from Mol)ile, show a fair percentage of germination. In some cases the tinal percentages of germination were even higher than tlie controls; but, as previously stated, the tinal germination is not always a good criterion for the determination of vitality, it Ijeing necessary to consider the germinative energy as a l)asis foi- comparison. In order to show this moi'C fully some of the dc^tailcd results arc hc^rewith gi\'en in Table III. These I'esults show' to a good ad\'antage the degree to which germina- tion has been retardcnl. 25037— No. 58—04 2 18 THE VITALITY AND OERMIISTATION OF SEEDS. Tahi,k til — RtittrddlKin in (jeriiibtation due t< cuiiditioiii iijiiri/ d III/ imfarorable clbnnt'ic Corn "A." Peas. Watermelon. Tomato. Place where seeds were kept. (iermi- nation at end of 64 hours. Final germi- nation. Germi- nation at end of 40 hours. Final germi- nation. Germi- nation at end of 84 hours. Final germi- nation. Germi- nation at end of 88 hours. Germi- nation at end of 107 hours. Final germi- nation. Control Mobile, Ala San Juan, P. R Baton Rouge, La . . Wagoner, Ind. T . . Lake City, Fla Durham, N. H Auburn, Ala Ann Arbor, Mich.. Per cent. SL3 4.0 64. .50. 64. 68. 86. 81). 82.0 Per cent. 94.5 20.0 92.0 88.0 90.0 92.0 96.0 88.0 98.0 Per cent. 79. (i " 24. 60.0 36.0 36.0 50.0 54.0 It 93. 7 82.0 I'er cent. 95. 7 44.0 98. 80. ,S0. 86. 94.0 97. 9 98. Per cent. 98. 0.0 12.0 0. 2.0 0.0 0.0 22. 94. Per cent. 99. 64. 88. 92.0 94. 92. 82.0 86.0 96.0 Per cent. 78.0 1.5 3.S. 5 9.0 40.0 16. 5 0.5 59.0 75. 5 Per cent. 92.7 12. 5 78.0 56. 81.5 65.0 5.5 75.5 91.0 Per cent. 97. 5 79. 5 96. 5 96. 94.0 94. 87.0 94.0 98.5 "After 62 hours. In order that the results of Ta)>les I and II ma}" 1)0 more readily and fully comprehended, it has been deemed advisable to summarize them in another ta])le. For this purpose the average percentages of germi- nation of all of the diflferent samples of seed have been determined for each of the different places. From these average percentages of ger- mination the deterioration in vitality, as shown l)y both the first and second tests as given in Tables I and II, have been calculated, the ger- mination of the controls serving as a ])asis for comparison. These results furnisli more trustworthv data as to the relative merits of the different localities as places for storing .seeds. Likewise the per- centages of deterioration between the time of the tirst and the second tests are shown in Table IV. Table IV. — Average percentages of germination of all seeds kept at the various places, their deviations from the controls, and the increased jjercadages of loss in the second series of Place of storage. Control Mobile, Ala. San Juan, P. R . Baton Rouge, La . Durham, N. H Auburn, Ala Lake City, Fla. . . . Wagoner, Ind. T . Ann Arbor, Mich. Average germina- tion of all seeds used in experi- ments. Deterioration in vitality as com- pared with con- trols. First test. Second test. First test. Second test. Per cent. Per cent. Per cent. Per cent. 87. 79 53. 59 86. 77 21. 31 38. 95 71. 98 ...j 68.21 '< 4.5. 18 ( ,..{ 21.39 " 47. 93 80.48 50. 86 8.32 41. 39 85.57 52. 42 2. .52 39. 58 85.70 .57. 34 2.38 33.91 83. 00 61.27 5. 45 29. 38 82. 12 62. 11 6. 45 28. 11 86. 23 84. 58 1.77 2. .52 Deterio- ration in vitality between first and second tests. Per cent. 1.16 51.61 9. 20 "39.86 36.81 38. 74 33.10 26. 18 21.37 1.91 a Calculated results. EFFECT OF CLIMATIC CONDITIONS. 19 III 'riil)le TV the results ufe arnuio-od in the order of tlic loss in vitul- ity as shown by the second tests. However, a few words of explana- tion will bo necessary, especially concernino- the loss at San Juan. In the first place, the seeds were kept at San Juan only J?>1 days" during the early part of the sunnner, while durino- the most critical period, Jiuie 20 to Noveni))er (!, they were in the ))otanical laborator}' of the University of Michigan. Those marked Mobile, Ala., were, during- the entire time, 2<>2 days, under the iuliuence of the warm, moist cli- mate of the Gulf of Mexico. The seeds kept at other places can well be compared with those from Mobile, the time being approximate 1}^ the same. The average loss as shown l)y the second tests was 3.35 times greater than the loss in the first test, which by calculation would bring San Juan next below Mobile, witli a loss of vital energy in the seeds ecpial to 47.93 per cent. But more data are necessary l)eforc such a gradation of injurious climatic influences can ])e established. Talkie IV, however, brings out another interesting point, as shown by comparing the results of the first and second tests at San ,Tiian and Mobile. In the first test the loss in vitality of the seeds from Mobile was 3S.9.5 per cent, while the seeds returned from San Juan showed a loss of only 14.31 per cent as compared with 71.98 and 21.39 per cent, respectively, as shown in Table II. The degree to wdiich the seeds were injured while they were stored in San Juan was such that the}^ continued to deteriorate nuich more rapidly than the control sample. This deterioration was most marked in tlie case of the pansy seed, the germination of the first test being 20 per cent and that of the second test only 6.5 per cent, showing a loss in vitality of 68.2 per cent and 87.7 per cent, respectively. Thus when seeds are once placed in con- ditions unfavorable for the preservation of their vitality for a sufficient length of time to cause some injury, this injury will alwaj's l)e mani- fest and cause a premature death of the seeds even though they after- wards be removed to more favorable conditions. Seeds of strong vitality can witlistand greater changes in conditions than seeds of low vitality without any marked detei'ioration. Through- out these experiments a wide difference has t)een observed l)etween the ''A'' sweet corn and the ''B'' sweet corn. The oi'iginal tests made «Tanuary 30, 1900, at the time the seeds were received, showed a germination of 94 per cent for the "' A'' sample and - ration in vitality as com- pared with the control samples. Per cent. 5.20 11.39 12. 17 12. .51 1.5.77 22. 67 26. 10 29. 58 43.56 .53. 89 74.10 84. 90 85. .85 In the above table the list of seeds is arranged in the order of their power to withstand the action of diverse climati(; conditions, as shown by the results of the second test, given in Table II. Tomato seeds were found to be the most resistant, the control .sample germinating 97.5 per cent. The average germination of the samples of tomato seed kept at the various places was 92.1:3 per cent, or a loss in vitalit}' of only 5.20 per cent. The seed showing the next least injury was the peas, with a deterioration of 11.39 per cent. The phlox, which was the most affected by the unfavorable conditions, germinated only 7.62 per cent, thus showing a loss in vitality of 85.85 per cent. It is also interesting to note that the order, as show^n by the second series of tests, is quite different froiu that of the first. This lack of uniformity increases the ditticulties that must be overcome before the causes of the loss of vitality in seeds can be fully comprehended. Were all seeds affected in the same way when subjected to identical con- EFFECT OF CLIMATIC CONDITIONS. 21 ditioiis, tho oihIci- should lia\e rciimiticd tlic sMinc throu^'hout, l>ut tho witlc variiitioii in :itiii().s[)lierir cliiin^cs iiirccts dillVrciit seeds so very diti'erently tluit no unil'onnity of I'esultsean I)(^ secured. For example, the conditions prevailin*^- from FeI)ruaiT until June were uuich more disastrous to the vitality of the tomato and pea than to the "A''' sweet corn, watermelon, and lettuce, while the conditions existing' from June to November were more injurious to the "A" sweet corn, watermelon, and lettuce. An examination of the table will show other results of a similar nature. During the earlier stagcss of devitalization seeds undergo a gradual deterioration in vitality, but after reaching a cer- tain stage in their decline there is a comparatively sudden falling otf, and seeds, except perhaps a few of the most persistent, soon cease to show any power of germination. Such factors as these must be taken into account in determining the relative length of tiim^ that ditferent kinds of seed will retain their vitality. But as yet sufficient informa- tion is lacking in order to make any trustworthy attempt to classify seeds in respect to their viable periods when subjected to different con- ditions. Numerous experiments are now under way, with the hope of furnishing a basis for such a classification. In order to o])tain more data as to the influence of climate upon vitality additional samples of seed were sent to Mobile and Baton Rouge, where they were stored under the same trade conditions as for the former experiment. For these tests only cabliage, lettuce, and onion seeds, put up in envelopes, as for the previous tests, were used. The diti'erent packages of seed, ]:)laced in paper boxes from which they were not removed, were sent from the laboratory on May 20, 1901, and were returned November 20, 1901, the total time of storage being 190 days. The results of these tests are shown in Table VI, and are even more striking than those of the former tests shown in Tables I and II. Table VI. — ■Reldtirr uwrils of Mohilc, Ala., Baifni Roiu/r, La., (ind Ami Arhor, Midi., «.s' jthiccx fur diiriiKj xceih. [Period, 190 days.] Cabbage. Lettuce. Onion. Seeds subjected to ''Trade condi- tions." Tercentage of seeds germinated at tlie end of — Percentage of .seeds germinated at tlie end of — Percentage of seeds germinated at the end of— 36 liours. GO hours. 14 days. 3G hours. 60 hours. 11 days. 60 hours. 84 hours. 108 hours. 14 days. Mobile, Ala Baton Rouge, La . . Ann Arbor, Mich.. 0.0 0.0 10.0 0.0 0.0 (il. f) S.5 2'1. 5 m. 5 ■ 0.0 'J. .s (17.0 1^,0 3'.. 5 ,S2. .S 64.0 74.0 0.0 0.0 3.0 0.0 0.0 10.0 0.0 0.0 43. 0.0 0.0 93.0 Table VI shows quite clearly the deleterious action of the warm, moist climate of the Gulf of Mexico on the life of seeds. The onion seed which was stored at Mo])ile and Baton Rouge did not germinate, 22 THE VITALITY AND GERMINATION OK SEEDR. while soed from the .same lot stored at Ann Arbor oei-niinated '.)?> per cent. The cal)l)ao'(' seed was injured nearly as mueh as the onion, the sample from jNIobile g'erminating- only 8.5 per cent. The conditions at Baton Rouge were slightlj^ more favorable to the preservation of vitality. The calibage seed stored at the latter place g-erminated 22.5 per cent, while a like sample of seed stored at Ann Arlior g-erminated 80.5 per cent. The lettuce was much more resistant than eithei- the cabbage or the onion seed, Init here, too, the injury was ([uite marked, especially as shown by the retardation in germination. The conditions at Mo])ile wen^ also the most disastrous for the lettuce seed. During the first 3() hours that the tests were in the germinating chamber none of the lettuce seed from Mobile germinated, while the seed from the corresponding- sample from Ann Arbor germinated 07 per cent. The final percentages of germination were Ott and 90. 5 per cent, respectively, for the seed from Mobile and Ann Arbor, showing a loss in vitality of 33.68 per cent in the seed stored at Mol)ile. Here it will be seen, as in Table V, that the onion seed was most sensitive and the lettuce seed most resistant to the unfavoral)le conditions. In the first tests shown in Table V the average loss in vitality of the lettuce, cabbage, and onion was 15.77, 43.50, and 74.10 per cent, respectivelv, while for the last tests, as shown in the foregoing table, the losses in vitalit}^ of similar samples of seed kept at Mol)ile were 33.08, 91.29, and 100 per cent, respectiA"eh\ The ratio is practically the same in l)oth cases, the loss in the cabbage seed being- 2.7 times greater than that of the lettuce. The foregoing- data are suflicient to indicate that climatic infiuences play a very important part in the life of seeds, and that the degree of injury varies greatly in difi^erent places and likewise in different seeds. Some seeds were practically worthless after an exposure of four or five months in such places as Mobile, Baton Rouge, or kSan Juan, as shown in Table I. After longer exposures, six or nine months, similar results were oljtained from all of the places to which seeds were sent. Man}^ of the seeds were killed, as shown in Table II. The conditions at Mobile were fatal to all of the seeds; that is, the seeds were worthless so far as the gardener is concerned. CAUSES OF THE LOSSES IN VITALITY IN DIFFERENT CLIMATES. Having shown that seeds lose their vitalitv uiuch sooner in some localities than in others, the question naturally arises, '"Why this loss in vitalit}^?" Unfortunately only two of the places where seeds were stored. Mobile and San Juan, have Weather Bureau stations which are equipped for making complete observations of the meteorological conditions. It has been observed, however, that there is a very close relationship between the precipitation and the loss in vitality in seeds; that is to say, in a measure the loss in vitalit}" is directly proportional to the amount of rainfall. This deterioration is more apparent as the OATTSES OE^ LORSEM TN VITALITY. 23 toin})or;iture iiicreiiscs, hut tlic injiii'v (luc to the iucrcast' in tcinpcM'ji- tiirc is (l('])(>ii(lont on the amount of moisture pi"oscnt. The following- table lias been compiled in order to show the ratio between the loss in vitality and the precipitation and temperature. 'rh(> loss in \italitv. as o-iven in the second c(dumu of Table Vll, rep- resents the average losses in percentages, calculated from the results of the o(>rmination tests of the 13 dili'erent samples of seeds, as shown in Ta])le II. " The third column shows the annual precii)itation in inches. The annual precipitation has been taken, ])ecaust^ in st)nu> instances heavy rainfalls occurred just previous to the time that the seeds were put into storage. Then, too, the annual precipitation furnishes more accu- rat(^ data for a basis of comparison. The mean temperatures, as given in column 4, avo not the mean annual temperatures, but the averages covering the time during which the seeds were stored. The mean annual temperatures were not taken, chiefly for the reason that the critical period, in so far as tempiM'ature is concerned, is during the summer months. Table VII. — Jinlio hctireeii vit((lifi/, jir^Tip'iloMoii, ami fciiipiTidure. '' P'laoc^ ■wlioro seeds \veri> stored. Mobile, Ala Baton Rouge, La. Durham, N. IF . . . Auburn, Ala Lake City, Fla Wagoner, Ind. T. Ann Arbor, Mieh Average loss in vi- tality of thelHdif- feren I sam- ples of seeds. IT Clltf. 71. '.IS ll.3recipita- tion. Lirlifs. 91. IS 0(1. ;'," IS. 20 (V2. CI ■19. 7(; ■12. 10 2S. .5S Temperature. Maximum Fahr. Ihyrees. 71.4 72. 2 .52. ;? (U. 4 73.3 (37. 1 49.12 Diyri 90. 9S. 9S. 9S. 103.0 107. 9S. "These seeniM ly, 190(-), and were returned tii llie Ixilauiial l;d)()ratory and tested in October aud Noxcinber, 1900. The average time that the seeds were kept at the various places was 2.''v2 days. ''Tlie results of the Sail Jtian tests have Iieeii (iniitted from this talile because, as has been pi\'viously stated, all of the seeds were returneil from San .liiau on .luiie 20, 1900, when the lirst tests were made. The second series of tests was made in October, 1900. During the time intervening between the first and seconil tests the San .luan samples were kept in the botanical laboratory at the University of Michigan. According to the table tlie seeds kept at Mobile snft'ered the greatest loss in vitality. However, it i.s quite probable that the greatest loss would have been from the seeds stored at San .Juan had the time of storage been tli(> same for the two ])laccs, so that the results of the San Juan tests could have been included in the table. This conclusion is based on the following facts: Normally, the number of rainy days at San .Tnan far exceeds those at Mobile. In U»00 there were 211 days on wdiieh rain fell in otiu .luaii, while the records for Mobile show only 1 lO. Likewise tlie average temperature of the dew-point Tor San Juan was 71° F. and only .')9° F. for Mobile, which, when expressed in terms of al)solute moisture, gives S.240 and ,')..'>."i.5 grains of water ]>er cubic toot at the time of saturation. On the other hand, the relative humidity of Sail Juan was 7s..'i per cent, or slightly lower than that of Mobile, the latter having a relative humidity of SO..T |>er cent. However, the mean annual temperatures were 77.i'i'^ and 71.4° F., respectively, hence a mc^aii ab.solute humiiiity of 7.099 grain.s of aqueous vajwr for San Juan and only G.71S grains per cubic foot for Mobile. 24 THE VITALITY AND GERMINATION OV SEEDS. From the foreooino- tubh^ it will be seen that precipitation is a factor of much greater iniportaiice than temperature. In order to show the real value which the amount of precipitation furnishes as a ])asis for judging- the length of time that seeds will retain their vitality when stored in localities having- a marked difference in the amount of rain- fall, the results set forth in the above table are ri'presented diagram- matically as follows: J^jj'rcl (if }irecij)itit vitality. Place. PercentiiKe of loss in vitality. Inches of precipitation. jNro))ne 71. 9S 91. IS Baton Rouge 41.39 (iCi. 37' Durham ■Ml r.s -18. 20 Auburn :!3. yi f)2. 61 Lake <^itv '29. 3.S •Js. -11 49. 70 Wagoner .' 42. 40 Ann Arbor 2.52 m 2S. M iiKMiB^HaiBBan A discrepanc}' is very marked for Durham, N. IT., which may be partially explained by considering again the conditions under which the seeds were stored. It will be remembered that these samples of seeds were stored in a hall which opened directly into a chemical labora- tor}'. It is (piit(^ probable that the low percentages of germination were due to the injurious action of gases emanating fiom the labora- tory. Of these gases, ammonia pi'o]>ably played a very important part, as it is well known that seeds are very readily injured wIkmi subjected to the action of annnonia. It is to be understood that the above comparisons are somewhat indetinite. If the amount of rainfall were equally distributed through- out the year a definite ratio could, in all probability, be established; l)ut in the majority of places there are alternating wet and dry seasons, Avhich make such a comparison very difficult and unsatisfactory. Yet for ordinary considerations it is sufficient to say that seeds will retain tlieir vitality much l)etter in places having a small amount of rainfall. For more exact comparison other factors must be taken into account, especially the relative humidity, mean temperature, and temperature of the dew-point, which ultimately resolves itself into the absolute amount of moisture present in the atmosphere. EFFECT OF MOISTURE AND TEMPERATURE UPON VITALITY. From the foregoing ^experiments it is quite evident that moisture plays an important part in l)ringing al)out the premature death of seeds and that the detrimental action of moisture is more marked as EB^FEOT OF MOISTTTRE AND TEMPERATTTRE. 25 (lie Icinpci'utiirc iiicrciiscs. Foriiici-iy the ^cinM-al consensus ot' opinion has hren to make this stateniont in the rcNcrso order that is, tluit teniporatun- exerts a very harmful action on seeds it' much moisture l)e present. For compairatively hiu-h temperatures the hitter statement Avoukl proha])ly suffice — at least it is not misleading-, and in a certain measure it is true; but at the lowest known temperatures, as well as at ordinary temperatures, moisture is the conti'oUini'- factor, and in order to he consistent it should likewise l)e so considered for higher temperatures — that is, within reasonable limits. That temperature is only of secondary importance is brought out in the results o])tained by a nmnber of investigators. It has been well esta)>lished ])y Sachs," llal)erlandt,'' Just,^ Krasau,'' Isidore-Pierre,*' flodin,-', Dixon, f^ and others that most seeds, if diy, ai'e capable of germination after being subjected to relatively high temperatures for periods of short duration. The maximum for most seeds is a tempera- ture of loo-' C. for one hour; but if the seeds contain comparatively large quantities of moisture they ure killed at nnich lower tempera- tures. It has been reported that lettuce seed \\\\\ lose its vitality in two weeks in some of the tropical climates where moisture is abundant. Dixon has shown that if lettuce seed be dry it will not all be killed until the temperatui'e has l)een raised to 11-1^ C. In case of low temperatures the factor of moisture is of less impor- tance, yet even under such conditions the moisture must not be exces- sive or the injury will be (piite apparent. But if seeds are well dried it can safel}' ])e said that they will not ))e killed as a result of short exposures to the lowest temperatures which have thus far been produced. Our knowledge of the resistance of seeds to extremel}- low temperatures is based on the experiments of Edwards and Colin, ^' Wartmann,' 0. De C'andoUe and rictet,'' Dew\ar and McKendrick,^ Pictet,'^ C De Candolle,'" Brown and Escombe," Selby," and Thiselton- "Ilandlmeh d. Exp. Phys. d. Pflunzen, Txnpzig, 18(35, p. (>(>. '' Ptian/.fnl)au I, 1875, pji. lOK-llT; Abs. in Bot. .TiUire.sljr., 1875, p. 777. <'B(>t. Zeit., IVA, .lallr<,^ 1875, ]^. 52; Cohii's Boitriiffe zur Biol. Bmssiai aJha (oily), PIsidii sativum (nitrogenons), ('itCiirJ>ilrv aiKl tlie seeds wei'(> exam- ined at once. Tliost'. contained in the paper })acka<4-es had a])sorl»ed a c()nsideral)le quantity of moisture and were much softened. In all of the packages except those containing- the onion and watermelon seeds some mold had developed; but in the seeds us(>d for the germination tests care was taken to avoid using those that showed any trace of a mycelium, there))}' reducing the injury due to fimgous growth to a minimum, even though sub.seqnent experiments have shown that such injury is practically negligible. An interesting point concerning the germination of some of the seeds at this low temperature may be stated in this connection. Eight of the peas, or 4 per cent, had already germinated, the radicles vary- ing in length from 1 to 2.5 cm,, thus corro))o rating Uloth's results in germinating peas at or slightly beloAV the temperature of melting ice.^' Tablk VIII. — Tlif ritalily of seeds kept in an ice Jtouse ineiiveloj^es (iiid holl/es, ami like- leise the vHnliti/ of the controls. First test after li G days. Second test, after 167 daj- (iermination. Differ- ence be- tween envel- ope and control sam- ples. Differ- ence be- tween envel- ope and bottled sam- ples. Germination. Differ- ence be- tween envel- ope and control sam- ples. Differ- ence be- tween envel- ope and bottled sam- ples. Kind of seed. Con- trol. Envel- ope. Bottlc. Con- trol. Envel- oi.e. Bottle. Corn ".\" l> 79. .'■■p 92. 100.0 .")2. T) 71.0 '..S. .SO. Prr el. ltd. (;o. 92. r> S9.0 5.0 73. 90.0 ]'rr ft. 91. 90. 90. 5 94.0 81 5 Pit ct. 110. 30.0 2. 5 4.5 Pa- ct. .58. 30. 4.0 .5.0 Prr (i. 92. 92. 95. 92. 80. 5 73.5 94.7 100. .52. .54. 96. 5 100.0 81.5 I'rr rt. H\. 74.0 94. 5 90. 74.0 .52.0 90. 0.0 11.0 .51.5 '.)G. GG. Prr ct. 9G. 94. 95. 94. 89. 96. 98. G5. 5 68. 5 96.0 100. 71.0 P(r cl. 6. IS.O 0.5 2.0 6. 5 21.5 4.7 100.0 49. 5 43.0 45. 4.0 15.5 I'cr cl. 10. Corn " B " 20. Onion 0.5 4.0 Radish 15. Carrot 80.0 88. ia).o 05.5 "10.5 2)i. 5 I'ea G.O Bean 98.0 I'nnsy Phlox 47. 5 GO. 5 G3.0 Tomato 93. 5 100.0 m. 22. 5 8.0 20. 5 10.0 44.5 Waternielon Lettuce 4.0 .5.0 Average «7.3 03. 87.9 25. 27.7 84.9 62. 1 87. G 24.3 27.0 "In making np the averages the result of the germination of the phlox was omitted because a sub- sequent examination showed that the bottle containing this sample of seed was broken at the bottom, thus admitting sufficient moist\ire to destroy vitality, as is borne out liy the second test. The above table shows, as previously stated, that the results of the tirst tests are incomplete and not very satisfactory, owing to the fact that the germination tests were imavoidabl}^ dehu'ed for eight da3^s after the seeds were taken from the ice house; but with the second set " Flora, 1875, pj). 2()6-268. 28 THE VITALITY AND GERMINATION OF SEEDS. of s;rm})l('s (lie counts for tlic vitality tests wore bei^'un within an liour from the time the seeds were removed from the ice house. Thus, the conclusions for these experiments must ])e drawn chiefly from the sec- ond series of tests. However, comparisons will be made with the first wdierc such seem justitiable. It will at once be seen that the seeds which were in paper packag-es gave a much lower percentage of germination than either the control samples or those kept in ))ottles. The average germination of the controls was S4.9 per cent, and the averag'e germination of the seeds kept in bottles was 87.6 per cent, whil(> only ()2.1 percent of the seeds kept in paper packages germinated. This is equivalent to a loss in vitality of 24.3 and 27 per cent, respectivel}', as compared w^ith the vitality of the control samples and the samples from the l)ottles. The results of the first tests are practically the same, save that the difi'er- ences between the control and the Ijottle samples are less marked. In the second case the average vitality of the seeds kept in envelopes was nuich reduced l)y the complete failure to germinate in the case of the beans, which are most susceptible to the deleterious action of moisture at the given low temperature. One of the most important points brought out by these experiments is the result obtained wnth onion, cabbage, and watermelon seeds. In both the first and the second tests the g-ermination varied but little throughout. Howev(n-, in all cases the seeds in the paper packages were slightly injured by the action of the moisture. This factor is of much importance, especially in the case of the onion seed, which, when k(^pt in a moist atmosphere at normal temperatures, soon loses its vitality, but when maintained at temperatures slightly l)elow freezing it becomes very resistant to the action of moisture. The beans, on the other hand, were all killed, although they are ordinarily much more hardy than onion seed. It is quite probable, however, that the death of the beans may be attributed to the reduction in tem- perature. Containing as they do large cpiantities of starch, they a])sor}) mor(^ water than less starchy or more oily seeds. This factor, together with the large embryo, renders them much more susceptible to the injurious action of freezing temperatures. Another important feature brought out by these experiments was the better germination of the seeds which had ])een stored in bottles in the ice house. The average germination of these samples was 2.7 per cent higher than that of the control. In a measure this may be included within the limits of variation; but when it is considered that all of the bottle samples except the ])eans, tomato, and lettuce showed a vitality equal to or greater than the control, it can hardly be considered as a normal \'ariation, especially since only the lettuce gave an}^ marked variation in favor of the control. Likewise, the average percentages EFFECT OF MOISTURE AND TEMPERATURE. 29 of the iir.st series of tests show ii slight iiicreuse in fa vol' of the seeds kept in the l)ottles, thou^'h the increase is not so well niar-ked and is less uniform than in those of the second series. Aside from the tinal g-ermination there is still another factor that must ])e taken into consideration as bearing evidence of the advantage oi keeping seeds at low temperatures, provided that they are kept dry. All of the samples that were stored in the ice house in bottles showed a marked acceleration in germination. It is (piite evitlent that the res- piratory activities and accompan3'ing chemical transformations were much reduced ]\y the reduction in temperature, and the A'ital energy was thus conserved; ))ut when the conditions were favorable for germination the greater amount of reserve energy in these seeds ga\e rise to a more vigorous activity within the cells and a correspondino' acceleration in germination. Numerous other experiments showing the effect of moisture on ttie vitality of seeds were made. In contrast to those just given, the injurious action of moisture at higher t(Mnperatures, yet temperatures well within the limits of those ordinaril}' met with in the handling of seeds, will be next considered. EFFECT OF IMOISTURE OX VITALITY AT HKiHEIi TEIMl'EUATUKES. This set of experiments was undertaken particularly to furnish con- ditions somewhat similai' to those existing in the States bordering on the Gulf of Mexico, or, in fact, all places having a relatively high degree of humidit}" and a temperature ranging from 80-" to 37^ C. (86" to 1)8.6-" F.) during the summer months. In ordei- to secure the desired degrees of temperature two incubators were utilized, one being- maintained at a temperature varying from 80 to 32 C, the other from 36"^ to 37-' C. The thermo-regulators were so adjusted as to admit of a possible variation of nearly two degrees in each case. Beans, cabbage, carrot, lettuce, and onion were used for these tests. In each of the incu])ators the seeds were subjected to four diU'erent methods of treatment: 1. In a moist atmosphere, in triM- coinimuiica- tion with the outside air. 2. In a moist atmos])h(M(\ but not in con- tact with fresh air, the seeds being in. sealed ])ottles of 250 cc. capacit3\ 3. In a dry atmosphere, in free communication with tho outside air. 4. Air-dried seeds in sealed l)ottles. In order to obtain the conditions requisite for the lirst method of treatment, an apparatus was used as shown in tigure 1. The seeds were put up in small packages and then placed in a 25<) cc. bottle. The bottle containing the packages of seeds was placed withi^n a specimen jar which was partially tilled with Avater. This jar was th(Mi closed with a hirge cork stopper which carried two glass tu])es, (^acli of I cm. bore. These tubes extended 25 cm. above the top of the jar and out through 30 THE VITALITY AND GEKMINATION OF SEEDS. ^^ the opening in the top of the incubiitor. The pi'iniary object of the tubes was to prevent an}' water vapor from escaping within the incu- bator and thereby doing damage to the seeds that were to be kept dry in the same incubator. For the same reason the cork in the jar was well coated with paraf- fin. Approximately the same volume of water was maintained in the jar throughout the ex- periment, more water being added through tube a, as occasion demanded, to replace the loss by evaporation. The chief advantage in having two tubes was the comparative ease with which the air within could be displaced })y a fresh supply by forcing a current of fresh air through one or the other of the tubes. Two such preparations were made, one being left in the oven maintained at a temperature varying from 30 ' to 32^ C. , the other in the oven maintained at a tempera ture varying from SB-' to 37-' C. In both cases the })ottles contained ti\'e packages of each of the five samples of seed, tiuis making provisions for testing at ditierent intervals. In order to suppl}' the conditions for the second method of treatment, similar packages from the same samples of seeds were put into 8-ounce bottles, which were then kept for five days in a moist chamber. The in- crease in weight due to the absorption of water within the five days was as follows: Beans, 3.03 per cent; cabbage, 8.09 per cent; carrot, 8.26 per cent; lettuce, 7.45 per cent, and onion 8.43 per cent. This increase, with the water already present in. the air-dried seeds, gave a water con- tent of 13.23 per cent for the beans, 13.99 per cent for the cabbage, 13.60 per cent for the carrot, 12.45 per cent for the lettuce, and 14.84 per cent for the onion. Th(^ bottles were then corked and sealed with paraffin, Ijut were so Fig. 1.— Apparatus used to (U-- tenninc the effect of moisture and temperature on tlie vitality of seeds in communication witli free air. Fig. 2. — Apparatus used to determine the effect of mois- ture and temperature on the vitality of seeds not in com- munication with free air. EFFECT OF MOISTMKE AND TEMrEKATHRE. 31 ('oiisti-iictcd thai the i'('l:iti\(' luiiiiiditv of (lie inclosed air could ))0. iiici'casod wi(liou( the axhiiissiou ol' more fi'(M' air. The detailed cou- structioM of this a])|)aratus is shown in lio-. 2." The seeds cont inned (o ahsorh inoistui'e to a Hunted e.xlcul. 1 u order that the iuidosed aii" unoht he uiaintaiued at ai)|)roxiuiat(d_v the same (Ictjfree of saturation, a ci'U(U^ hy^roscopcMvas attacluMl ou th(> inside of each l)ottl(\ These h y_nTosc<)})es were made from awiis of S/Jjxr C(t2>'ll(il(i L. , th(> tip of th(> awns heino- i-(Mnoved and a short piece of lino co])])er wire us(h1 as an indicator. These hyoi-osco])es wiM'e sus])end(Ml from the under side of the cork, as shown at //, and i>\ \\\v side of eacii was sus))ende(l a tine fihei' of silk, which, beini;' carried around l»\- the indicutor, i'ecord(>d th(> numbcM- of turns made by tiie awn. V\\y' such })i'e])ai"ations wei'c made for eacli of tJie two sets, so as to furnish seeds foi- a stM'ies of tests. One set was ke})t at a tem])(M'ature of 30'^ to 82 (I, the other at 80 to 37 C. The ^i^x^d fi-om one of tiic bottles, at each of the t(MU])eratures, was wei,i;"he(l after eiy'hty-oiK^ days, at tlu^ time the o(Miuinatiou tests were made. These wcd^hin^'s showed that at the h)wer t,emp(»ratures the a\<>ra_n'e increase in w(Moht for all the seeds was S.() per cent, and at th(> higher tempei-atnres. (I.I) per cent. The increase in the case of the beans was (|uite mai'ked at this time, bein per cent for those maintained at a temj)eratui"c ninoing- from 30 to 3:^ C, and !>.S piM- c(Mit for those maintaincMl at 30 to 37 ('. The third set of conditions consisted siiujdy of i)a('kayes of the air- dried seeds ke])t in ojxmi boxes in each of the incubators. This series of tests was made especially for the [)uri)ose of det-ernuninti' the etl'ect of dry heat on the \ itality of schkIs when maintained at the tempera- tures above o-iven for some consid(M'able time. Foi- the foui'th sei-ies small packag-es of the seeds were put into U-ounce ])ottles, which werc^ then corked and sealed with ]iarallin. Fi\c of these bottles were k(^pt in each of the ovcmis and y(>rmination tests were made at irrea'ular intervals. The results of these tests fu rtush a « The wiile-mouth l)<)ltle (/*) contiiins the paclvages of seed (.s-)- Tlnoiifj;!! an ' give off a(iueous \apor, which can escaj)e through the small opening (o) into the bottle. When suflicient moisture is present the supply is shut nff by pushing the stopper down linnly against the constriction. The .stopper must be well coated with va.s- eline to prevent its sticking to the sides of the glass tul)e. To make the apparatus more secure against the entrance of fresh air, a second piece of i-nbber tubing (r) is j)lace(l in Ww, upju'r jiart of thc^ glass tube, the to|i of w hich is then tilled with oil. 32 THE VITALITY AND GERMINATION OF SEEDS. basis for compariiiu- the relative merits of keeping" seeds in open vessels anottles. Table IX will show the eli'ect of the various methods of treatment on the vitalit}' of the seeds. Tai'.le IX. — ]'ilaliri/ of seeds irlu-ii. siihjecled lo Ihe dctioii of (i dnj aud a moid ahnosplierr^ both irlieii e.eposed to free air and irjien confined in (/hiss Injttles^ at reliitirehj high temperatures. « Kind of seed. Beau.. Do Do Do Begin- iiiiiK of experi- ment. End of e.xperi- mentand date of I tion tusts.i Dura- tion of ex- Mar. ...do. . . .do . ...do. Cabbage . . Do ... . Do . . . . Do . . . . Carrot Do ... . Do ... . Do ... . Lettuce . . . Do ... . Do . . . . Do . . . . Onion Do . . . . Do ... . Do ... . ...do. ...do. ...do. ...do. ...do. ...do. ...do. ...do. ...do. ...do. ...do. ...do. ...do. ...do. ...do. ...do. Apr. Ma,y May July Apr. May May July Apr. May May July Apr. May May July Apr. May May July Daija. 31 (19 M 110 \M (19 Vitality of seeds when kept in a moist at- mosphere. In open bot- i\e9., at tem- peratures varying from — In sealed bottles, at tempera- tures vary- ing from — 30° to 36° to'30° to 36° to 32°. 37°. 1 82°. 37°. .SI 110 31 12 69 21 SI 22 MO 31 12 69 2-1 81 22 140 31 12 69 24 SI 22 140 P. ct. 100.0 97. 5 94. 2.3 S7.8 71.6 SO.O 0.0 83. h 69. T) ■!8. 0.5 92. 5 38. 55. 5 0.0 95. 5 68. 59. 5 0.0 P. rt. 100.0 0.0 90. 5 0.0 77.5 0.0 90. 5 0.0 89.0 0.0 P. rt. 78.0 75.0 0.0 0.0 73.0 30.0 1.0 0.0 5-1. 5 0.5 78. 44. 5 1.0 1.5 61. 5 2.5 0.0 0.0 30° to 36° to 30° to 36° to 32°. 37°. 32°. 37°. P. ct. 44.0 0.0 0.0 0.0 72. 5 0.0 0.0 0.0 29. 5 0.5 0.0 0.0 .58. 2.0 0.0 0.0 •15.0 -0.0 0.0 0.0 Vitality of seeds when kei)t in a dry atmos- phere. In open boxes, at tempera- lures vary- ing from — In sealed bottles, at tempera- tures vary- ing from — P. rt. 86. 100.0 98. 100.0 86. 5 67. 5 89. 81.0 84.5 82. 11.5 81.0 91.0 42. 65. 82. 95. 5 97.0 95. 5 90.0 P. rt. 84. 90. 90. 9-1. Sl.O 87. 9 92. 83.0 88. 8,5. 50.0 81.2 86. 5 38. 5 58. 5 87.0 93. 95.0 94.0 92. P. rt. 98. 92. 5 98.0 98. 83. 5 79. 92. 5 88. 5 89. 5 83. 5 50. 78. 5 91.5 38.5 62. 5 81.5 96.0 97.5 99. 97.5 (ier- mina- tion of con- trol sam- ples. P. rt. 98. 95. 100.0 96. 86. 9 78.5 92. 86.7 89.0 82. 5 48. 83.1 90. 51.5 67.0 88.0 97. 5 93.0 95.0 94.7 P. rt. 94.0 98. 7 98. 99. 4 91.0 S3.0 92. 5 93. 1 92. 5 78.0 61.5 S3. 1 90. 31.5 53. 5 79. 9 96.0 98. 5 96. 5 95. 4 1> days, showed that all of the seeds from the open, moist chamber, at the higher temperatures, had been previously killed as a result of the drastic treatment; conse- quently no future germination tests were made. Those maintained at the lower temperatures were almost entirely free from mold at the expiration of the experiment, only an occasional seed showing any trace of fungous growth. Nevertheless, germination tests showed that the vitality had been destroyed in the ca))l)age, lettuce, and onion. Beans and carrot were most resistant, the former having germinated 2.3 ])er cent and the latter 0.5 per cent. All of the seeds had become very much softened. The beans and the lettuce had changed very materially in color, the beans (Early Kidney Wax Six Weeks) having become nmch darker and the lettuce (Black-Seeded Simpson) almost a hnnon color. With the seeds constituting the second series, i. e., ni a moist Kfnios- ji/i, r< Imt In scaled hottleK:^ the injury was much more severe. Here, as with the open chambers, the seeds subjected to the higher temperatures were killed lirst, even though the amount of moisture actually absorlu'd was less, as was also true with the other series. A weighing made- at the end of SI days gave an increase of 8.0 per cent for those from the oven maintaijied at a temperature of 30" to 32" C. , and 0.3 per cent at the higher temperature. Likewise, in this series, the seeds had become very much softened and a very disagreeable odor had developed as a i-esult of the putrefaction of their nitrogenous constituents. A close examination made at the end of 81 days revealed slight traces of fun- gous growth, but then> is no reason to l)elieve that these played any part in the destruction of vitalitv. However, in making counts for germination tests all molded seeds were carefully discarded. The results of the germination tests showed that the vitality of the seeds kept at the lower temperatures had ])een practically destroyed at this time. The ]>eans and onions failetl to germinate, while the 25U37— No. 58—04 o 34 THP] VITALITY AND GERMINATION OF WEEDS. ciib]);iji;o, carrot, and k'ttucc »^erniinate(l only 1, 2.5, antl i per cent, respectively. During" the succeeding (JO days nuicli mold liatl developed, and at the expiration of the experiment, 140 days, only the carrot and the lettuce gave any indications of vitality. It is especially interesting to note with what rapidity the deterioration took place between the sixty- ninth and the eighty-first days, showing that Avhcn vitality reaches a certain point in its decline there follows a comparatively sudden death. This same fact is also shown in the case of those seeds in this same series kept at the highei' temperature. After 31 days' treatment they all failed to germinate, except 0.5 per cent in carrot and '•2 per cent in lettuce seeds. In the two series of experiments just considered there was an increase in water content as a result of the humidity of the air in which the seeds were kept. But the third series, (/j)cn and dry^ presents (juite another factor. A weighing made at the end of 30 days showed that there had ])een an average loss of 2.5 per cent for the lower tempera- tures and 3.5 per cent for higher temperatures. After this time the weight remained nearl}^ constant. Subsequent experiments, which will be considered later, also show that the water capal)le of being expelled at any given atmospheric temperature is driven oil in a coni- paratively short time. In case of seeds this condition is practically completed in eight or ten days when maintained at temperatures as above given. This extra drying of the seed causes a greater contrac- tion of the seed coats, and in a number of cases a corresponding retardation in the rapidity with which germination takes place. The retardation in the germinative activity is dependent on the increased difficulty with which the seeds absorb water, and in man}^ cases has an important bearing on the vitality tests. The fourth and last series, in which the air-dried seeds were sealed in bottles and subjected to the temperatui'es at which the two ovens were maintained, gave still another very different set of conditions. Here there Avas also an increase in weight, due probably to some process of oxidation, but the increase was very slight. The average increase from those kept at either of the temperatures was less than one-half of one per cent. Seeds, if Avell matured and thoroughly air-dried, are not injured when kept at temperatures below 37° C, whether they be kept in free communication with fresh air, or in sealed l)ottles, or tubes. In the experiments under discussion the average percentage of germination was slightly higher in the case of the seeds which had been stored in the sealed bottles. The mean percentage of germination for the seeds which had ])een exposed to the open air at a temperature of 30° to 32° C. was 83.05 per cent. Those from the sealed bottles kept at the same temperature germinated S4.82 per cent. At the higher temper- atures — 30 -' to 37'^ C. — the mean germination of the seeds from the open EFFECT OF MOISTURE AND TEMPER ATTHiE. .35 and the closed l)ottle.s was S2.()S and 85. (i2 percent, respectively. The control sample germinated 85.45 per cent. That 87"^ C is about the maximum temperature at which air-dried seeds can be stored without injury is shown by the followini^' experiments. Preparations similar to those alwvo mentioned were used, and after l)eing" sul)jected to a temperature of 37"- C. for 2ll> days, there Avas no appreciable loss in vitality, except the deterioration of 4 per cent in the case of the cabbage seed that was kept in an o])en bottle, and ij.'S per cent in the seed from a closed ])ottIc." But by increasing- the tem- perature, durino- an additional period of »)8 days, from 37^ C. to a maxinuuu of 44'-' C, the injury was nnich more marked, especially in the closed ])ottles. In the open bottles the vitality of thecal)bage was lowered from 5)1.3 per cent to 77 per cent, representing- a loss in vital- ity of 15. GO per cent. The onion seed fell from ;»5.7 per cent to 87 per cent when kept in an open bottle, and to (51 per cent when kept in a closed bottle. The beans showed no apparent injury in eithtu- case, except that tli(\y ))ecame very dry; consequently there was a retarda- tion in o-ermination as a result of the slow al)sorption of water. The o-nniter loss in vitality of the seeds kept in the ])ottles was the direct result of the hi^-her humidity of the air immediately surroundino- the seed, and not l)ccause there was ;i deficiency' in the supply of fresh air, as migiit be readily assumed. In the open receptacles the tidditional amount of free water expelled, as a result of the increase in tempera- ture, was allowed to escape, while in the sealed bottles it only oave rise to a relatively moist atmosphere, and conseiiuently to a premature death of some of the seeds. If seeds are to be so confined, they should be previously dried at a temperature at which they are to be stored. All of these seeds had become very dry and brittle. The odor of the air confined within tlu' sealed bottles luid l)ecome very unpleasant; likewise there was a marked change in the color of the seed coats of the inclosed seeds. SUMMARY. Most seeds if kept dry are not injured by prolonged exposures to temperatures l)elow 37'-' C. (98.6'-' F.), it being inunaterial whether they are in open or in sealed bottles. If the temperature be increased above 37"^ C, vitality is seriously reduced. If seeds are kept in a moist atmosphere, a temperature even as high as 30" C (SG'^ F.) works uuich injury in a comparatively short period. The degree of injury rapidly increases as the temperature rises. Provided the degree of saturation is the same, the deleterious eti'ect of moisture is fully as great in open as in closed l)ottles. "Only cabbage, onion, and beans were used for this experiment, the carrot and the lettuce seed being omitted. 36 THE VITALITY AND GERMINATION OF SEEDS. THE EFFECT OF DEFINITE QUANTITIES OF MOISTURE ON THE VITALITY OF SEEDS WHEN THEY ARE KEPT WITHIN CERTAIN KNOWN LIMITS OF TEMPERATURE. The results of the ex})erinient,s ju.st discussed furnish a fair criterion I)}' which to judge the vitaHty of seeds when inHuenced l)y tempera- ture' and moisture. It was still necessar}' to determine the effect of definite quantities of moistiu-e on the vitality of seeds when they are submitted to temperatures well within the limits of that which may be encountered in counnercial transactions. On Decem])er !!♦, 1900, preparations were made to determine these factors. Seeds of ca])bage, lettuce, onion, tomato, and peas were used for these experiments, which continued for TO or 72 days. All of this seed was of the harvest of 181)9 and had been in the laboratory during the eleven months immediately preceding the setting up of the experi- ments, being thus thoroughly air-dried. The amount of moisture present in the seeds at this time, as indicated by drying at 100'-' C, was as follows: Cabbage, 5.90 per cent; lettuce, 5 i)er cent; onion, 6.-11 per cent; tomato, Ir.Tl per cent, and peas, 8.-1-1 per cent. The preparations were made as follows: [a) Air-dried seeds were placed in bottles of 125 cc. capacity. The })ottles were closed with cotton plugs in order to protect the seeds from dust while permitting a free circulation of air. This set served largel}^ as a check. {h) Air-dried seeds were carefully weighed and then ])ut into 125 cc. bottles, closed with firm corks, and sealed with paraffin. {(\ d, c, and /') These samples were also carefully weighed and sealed in bottles as I, but in the ditl'erent series of bottles there was first introduced 0.5, 1, 2, and 8 cc. of water which had been })reviously absor])ed ]»y small strips of lilter paper. {(/) The seeds constituting this series were first dried for 30 days at a temperature of from 80- to 82 C. and then put up in Iwttles which were sealed with paraffin. The loss in weight as a result of the dry- ing was as follows: Cab))age, 2.41 per cent; lettuce, 2.59 per cent; tomato, 2.71 per cent, and onion, 3.47 per cent, leaving a water con- tent of only 3.49 per cent, 2.41 per cent, 2 per cent, and 2.94 per cent, respectively. (Peas were not included in this series.) One of each of the al)ove preparations was then subjected to different degrees of temperature as folloAvs: (1) Outdoor conditions, protected from rain and snow, but freely subject to all changes in temperature and humidity. The temperature during the time of the experiment, Decem])er 19, 1900, to February 28, 1901, varied from a iiiininumi of —21.(5'^ C. to a maxinuim of 8.9" C. (2) In a fruit c(41ar having a comparatively low and uniform temperature ranging from 10-^ to 18- C. EFFECT OF DEFINITE QUANTITIES OF MOISTURE. 87 (;>) In the "dark room" of tho botanical laboratovv, which was quite dry and maintained at a temporaturo of 2<) to )i"2 C (4) In tho lierharium room on the fourth floor of the botanical labo- ratory. The air hero was very dry and tho mean tompei-ature about tho same as for No. 3, but with a much wider variation, roachino- at times a maximum of 30' and a minununu of 10 ' C (5) In an incubator maintained at 30'^ to 32' C. (0) In an incubator maintained at 37 to 40 C. It will be observed that all of tho preparations, except Nos. 1 and 4, were kept at temperatures which were quite uniform. The increase or decrease in the weight was determined at the expiration of To or 72 days by again carofull}' weighing- the seed, after which germination tests were made. The results of the germination t(>sts and the gain or loss in weiiiht are o-iven in Ta))le X. 38 THE VITALITY AND TERMINATION OF REEDS. 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"' C-J r-i r-H rH rH r-H CO CO CO Ol iM* C^ lO I O -1< ^ a j O iC O O iC lO lO O O lO lO O uC O O iC O O lO O O O O O iC o o H!--r-i;:occ'i^icxicciidcotor>^toQ6aicorHtDto*i>-i^coor^ •sjnoi{ or.x j*> p"'"» ^»n ^v iC, O O O lO U7) lO lO lO iC O O iC lO O O lO iC uTT' O iC lO O iC O iC o o o^ o CO ai X* 1/5 r^ oi t^ i^ -t^ t--^ oi to -t* to ^-^ oi o ic* x' -T^ i-* C3 o x 1^" i^ X C-- X X X X I'- Oi-X X CC 1^ »C X X X X to r-i X' X; X X »-i OC X -t* •sjnoq /.i JO puo oq] -jy iCOiOOiCOiOOiOOOiCiCOiCOiOiOOOiOiOiOOOOOiO ci --0 X co' ■'j^ CO to ic to i^ r^ X* c^i CO CO r-^ CI CO o -1^ -f oJ T-H o o (M C^l T-H -M (M ri T-H CO » i-i CO ri c^ fH •SOp)oq Ul pOSOl.)UI OJOAV SpOOS 0[lllAV 'jqJBIOAV Til OSTJOJOIII JO OSinil^^J^cI MO iC -t* CO --H -M r^ to iC Oi oi r^ xxifrciCiCi t^iOiOiCtCOOiOOiCiOOiOOOiOO'COOOOiCOOiCO'C oai^-^o^coc^^cotcocJil--^Oix'^^C5cococ^^^l-^x*x*I■^coococo-l^ QC l^ CC GO X GC X t^ X' l^ CO 1-* to l"- l"^ CC CO I- iM X t^ t^ t^ »C XX I- '• '• \ \ '• . ^(iJxtOtOCOi-HCi-l^i-i-t'-fO-tCOLCCl-^CO-t^'Mi-H . . . . . . .f5i-i(Mi-(i— ii-tx-p-fo-fc^coor-coc^cococii^ I • • '• '• ' '0oOOOOr-^rHt-MrHrHi-HC0C0ai-C lO lO to iC iC lO to iC iC iC c^i to O iC »o C^ 1- iC lO to to to C-i . to X T-H 'O t^ iC I^ -f^ X -M CO to -t^ Ol *: • O O f-H i-H i-H O - • OOOOO Or 5 iC X' X Oi lO CO O -^ CI O l^ X -t^ to CO O O 1— I i ^ ^ r-I --H CO c-i cj c-i ci c-i ic »o "O lOiCiCiOiOiOOOOOOOOOO ■ r-, ^ i_ ■c o CJ 0 IC lO iC iC »o > *C lO »C lO EFFECT OF DEFINITE QUANTITIES OF MOISTURE. 39 ooooooooo o -r o o o x x -t^ o • ■ ' ■ • ■ ■ o lO en o X x 000000000 '<'...'..' 0 iC lO cc* I'- c^i C"i "C -1* CO — f" o ci Oi ^o r- lO ic ~t" iC iC O lO iC lO iC O O »^ O iC O lO >c o ■^ x' O O O 1-H r^ »C O CO iC -i^ QC oi t-* x> t^ X) t-^ CO l^ l^L^zD^JD '^ t^ MOOor^oo-X)oocoocox;--t Oi COClCl jmOO ^^i-H'X ir^c^'ooo>a>cocicio Coo^oo OOOOOiOOOOiCifTOvCOiOiC i-i -1^' o ic "T^ o CO o o CO o? o lO cj ai ci a> oj 'X t-^ Ci X> Oi as CT> OC' Oi lOOOiOiCOiCOOOOiftiOid^O ci ooos-i^'-i5a>ooaiGCr4-t^oi-^-f< 1- I— X lO iC l- t^ X^ OC l^ t^ X iCCiT-ICIOCOOOCOQC oJr^cici <1JX> (X i-H X' o 00 1^ ai CI -f cj J- CI o o 5:^10 ■T* ic -r r^ o -^d cJ t-^ CO o ^' o o o ^ o OiOOOOiOiOOOiCOOiCOOO cdccocioicot^oococicioaJ'-Ico CO ojooooi^ occ^'aiaixaioj iCOOOiCOOOOiCiOiOOOOiO «^ o o ci CI ci o o o t-^ CI CO o o o 06 C^ iC »C CI rH lO »C -sO 'C ^ri 10 »0 CO t-H cJ o o r- a> ^-H OS CO o X' CI a5 oJ o COt^CO>OiOCOiCi-OX)CO>- O r-I O r-^ Cl CO -^ iC* CO rHr-3.5 per c(Mit and of the latter iMI per cent. All of these tests gave Hnal per- (•(Mitages of germination somewhat highei' than the mean of the control sauiph^s. But the g(>rmination was consideral)ly retarded, the control samples having gei-minated 29.5 per cent dui'ing the first 77 hours. These retardations in germination nuist be due to a lowering of vitality, as a more careful study of the table will sliow, and not to any excessive drying that may have taken place dur-ing the time of treatment. Numerous other examples are to be found in the table, some even more striking than those mentioned, but it is not deemed necessary that the3^all be pointed out and discussed here. The table also shows the results of the ^•arious weighings made of all of the different samples which were kept in closed bottles. With but very few exceptions there was an increase in weight, which iiu'rease was qnite marked in all cases where free water was introduced. The aii"- dried seeds that were sealed in bottles without the introduction of free water all increased slightly in weight, with the exception of the peas, Avhich showed a slight decrease in weight. It has been ol)served that the absolute loss in the weight of the peas Avas slightly greater tlia!i the total gain in the four other samples of seed. This, however, is not of sufiicient uniformity throughout to fully justify the conclusion that cab1)age, lettuce, onion, and tomato seed have a greater affinity for wat(M- than peas, and that the formei- ro])bed the latter of a portion of their water content. Yi^t a portion of the increased weight of the cal>bage, lettuce, onion, and tomato seed is probably best accounted EFFECT OF DEFINITE (iUANTITIF:S OF MOISTURE. 41 for in that way. On the other hand, it is quite pi-ol»al»h> tiiat a por- tion of the increase in wei<2,htwas due to the results of intraniolecuhir transformations and to the coexistent respiratory activities of the seed. The means of making- tliese determinations are far from eas3\ Van Tieghem and (J. Bonnier have shown" that seeds kept in sealed tubes in atmospheric air increased in weight during two years, but the increase a\ as xer} small. In their experiments the peas which were in sealed tubes increased ^ Jjr <>f their original weight. A corresponding sample kept in the open air increased .-V of its original weight. Nos. 1540 to 15-1-5 in Tabh> X show an increased weight in seeds when sealed in bottles for To days. These seeds were previously dried for 30 days at a temperature of P>0 to 32 ' C Disregarding the increase in weights as above given and the factors to which such increase may be attributed, it is (|uite evident that in all cas(\s where water was added the increase in weight was Auo chiefly to the absorp- tion of the water. The absolute increase was api)i'oximately the same as the weight of the watin* added. The amount of water absorbed by diU'eivMit seeds varies greatl}' under identical conditions, depending lai'geiy upon the nature of the seed coats and the composition of the see(l. The av(M'ag(> increase in weight of the seeds used in these ex})eriments was as follows: Onion, 6.27 per cent; pea, 5.51 per cent; ca])bage, 1.12 ])ei-cent; lettuce, 3.1H) per cent; tomato, 3.1H» per cent. The loss in vitality of the corre- sponding samples was 2S, 12, 23.7, 18.5, and 14.7 per cent, respec- tively. The relationship here is quite (dose, the amount of water absorl)ed being roughly proportional to the loss in \itality. The penis, however, afford an exception to this general statement. But it nmst be rememl)ere(l that peas require a nuich lai'ger ]^(M-centage of moisture to start germination and are likewise capable of undtM-going much wider variations than the other secnls in (juestion. However, before a dt^finite ratio can \)e established between the absor})tion of water and the loss in vitality, many other factoi's nmst !)(> tak(Mi into consideration, such as the composition, water content, and duration of vitalit}' of the seed under natural conditions. Another interesting factor is shoAvn in No, 1540 of Tal)le X. These seeds were dried for 30 days at a temperature of 30 ' to 32' C'., after which they were kept in an o])en 1)ottle in the laboi-atory for 40 days. During the 30 days' drying th(^ cabbage lost 2.41 percent, lettuce 2.51) per cent, tomato 2.71 per cent, and the onion 3.47 pei- cent of moisture. These same seeds when exposed to the free air of the lal)oratory for 40 da} s never regained their original Aveight, the incr(>ase being as follows: Cab])age, 0.6 per cent; lettuce, 0.58 per cent; tomato, 1.56 per cent; onion, 0.89 per cent. 'I'he average quantity of water expcdied was 2.79 f'Bul. Soc. ])ot. France, 29: 25-29, 149-15;;, 1882. 42 THK VITALITY AND riKRMINATTON OF SEEDS. per (-out in ?>() days, while tlio aver:io-o ineroaso in weight (luving-tho -iO da^^s was onij^ 0.91 per cent. These results show that if seeds are once carefully- and thoroughly dried, thej^ will remain so; that is, if kept in a eomparatiyel^y dry room. This is an important factor in theprcser- yation of vitality, as is ])orne out in the results of the germination tests. Later experiments were made with very similar results, and an analogous method of treatment promises to be of much value as a preliminary handling of seeds. It is not detinitely known to what this stronger vitality is due, whether it be simply to the etlect of the dr}'- ing or to some process of chemical transformation which makes the seeds more viable. These results are now" under consideration and will be reported at some future time. The table also shows in a very striking degree the decrease in the number of germinable seeds with an increase in the moisture and temperature. The amount of moisture absorbed l^y the seeds, with a limited amount present in the bottles, was inversely proportional to the temperature. At the higher temperatures the iliclosed aii- held a larger portion as water vapor; however, there wiis a greater deterioration in vitality. Where the seeds were kept outdoors at the low temperatures ( — 21.0'' to 8.9° C.) of the winter months, no injury was apparent except where 3 cc. of water was added, and then only the onion seed was affected. This sample of seed had absorbed a quantity of water equal to 10.88 per cent of the original weight, whicli together with the original water content (6.4:1 per cent of the original sample) made 17.88 per cent of moisture in the seed. Practically the same results were obtained with the seeds kept in a fruit cellar at a temperature of 10° to 13- C. The samples of this series, in the open bottles, were also injured, as has been pointed out. With the samples that were stored in the dark room and in the herbarium room, the injury was more marked as a result of the higher tenqierature; but even here the seeds in the V)ottles which contained 0.5 cc. of free water deteriorated ver}' little. The injury was confined to the onion seed, which showed a slight retardation in germination. Where 1 cc, 2 cc, and 3 cc. of water were added, vitality in some instances was likewise remarkal)ly well preserv^ed. The lettuce, tomato, and peas gave no indications of any deterioration save in the bottles containing 3 cc. of water. Here the lettuce and peas were permanently injured, while tlie tomato seeds suft'ered only sufficiently to cause a delay in the rapidity w^ith which they germinated. The cab1)age seed was retarded with 2 cc and a lowering of the final percentage of germination with 3 cc. of water. The onion seed, being very sensitive to these unfavoi'al)le conditions, deteriorated very greatly, being practically worthless where 3 cc. of water were added. A l)rief study of the table will readily show that many seeds were killed at the still higher temperatures of 30 to 32' ' C. and 37- to iOo C. The onion seed was slightly injui-ed even where KFFEOT OF DEFINITE QUANTITIES OF MOISTURE. 4o no water was addod. However, a temperature of 40^ C. is suilicient to injure many seeds, even thoug-h the liberated water be permitted to escape, as is shown in the tests of the onion, No. 1539 of the table. The greatest injur}" when air-dried seeds are sealed in bottles and then sul)je<'ted to a Jiigher temperature is due to the increased humidity of the confined air, as a result of the water lil)erated from the seeds. At first glance some of the conditions given in the above talile may seem to be extreme and far beyond any normal conditions that would be encountered in the ordinary handling of seeds. This may seem to be especially true Avith tlie seeds kept in the bottles with 8 cc. of water where the additional amount of moisture absorbed gave ris(\ in some of the seeds, to a water content of approximately ^o per cent. Yet this need not be thought of as an exception, for such extrcMue cases are often encountered in the commercial handling of se(>ds. During the process of curing even more di-astic treatnuMit is not infrequently met with, Pieters and Bi'own" have shown that the common methods employed in the harvesting and curing of Pon jnut- ten!()0 the muximum temperature at Waf^oner, Ind. T., was 107^ F. (41.1'^ C), while that of Lake City, Fla., was 103° F. (39.5° C). If these points are kept in mind, it is not at all surpris- ing- to find that seeds lose their vitality within a few weeks or months in warm, moist climates. In order to make the above facts more clear the preceding table has been summarized and is presented in the following condensed form, showing the relation of the water content of the seed to vitality: Tahle XI. — Mdrlcid (hiirioTdtimi in vitality 'ivith an increase in the (jiKoilIti/ e no doubt that moisture is the prime factoi' in causing the premature destruction of vitality in seeds in the usual conditions of storage. Why they lose their vitality :is a result of the unfavoral)le conditions is ((uite a difl'er- ent question, and has to do witli the very complex com})osition of the seed. A COMPARISON OF METHODS OF STORING AND SHIPPING SEEDS IN ORDER TO PROTECT THEM FROM MOISTURE AND CONSE- QUENTLY TO INSURE A BETTER PRESERVATION OF VITALITY. SUOGESTIONS OF EARLIER INVESTIOATOHS. As early as 1832, Aug. Pyr. De Candolle'* wrote a chapter on the conservation of seeds, in which he said that if seeds be protected from moisture, heat, and oxygen, which are necessaiy for germination, their vitality will be much prolonged; moreover, that if seeds are buried sufficiently deep in the soil, so that they are protected at all times from the very great influence of oxygen and moisture, their vitality will ))e preserved for a much longer period. «Physiologie Vegetale, Paris, 1832, Tome II, p. 618. COMPARISON OF MP:TH0DS OF STORING AND SHIITING. 45 Gij^lioli" ooes so far as to i^iiy: There is no reason for denying the po.ssil)ility of tlie retention of vitality in seeds preserved dnring many centuries, such as the Mummy wheat and seeds from Pompeii and Herculaneum, jirovided that these seeds have been i)reserved from the begin- ning in conditions unfavoral.)le to cliemical change. * * * The original dryness of the seeds and their i)reservation from moisture or moist air must be the very first conditions for a latent secular vitality. Some of tlic earliest suoo-estions for storiiio" seeds in ([luiutity were made by Clement and Faz^-Pasteur, and were reported l)v Ang'. Pyr. De Candolle in liis Physiolog'ie Vej^'etale. Clement sno-o-^sted the use of laro-e east-iron I'eeeptaeles, made impervious to air and water, the well-dried seeds to he pouivcl in through an opeinno- at the top, after which the opening should be hermetically sealed and tiie seeds with- drawn through an iron pipe and stopcock at tlie bottom of the taidv. The scheme of Fazy-Pasteur was to store seeds in wooden boxes well covered with tar. This method was especially applicable to small ([uantities of seeds, and was used to a limited extent at that time, but, so far as has been ascertained, it has long since been discarded. The keeping of seeds in large iron tanks, as suggested ])y Clement, lias never been practiced to any extent. It seems quite possible, however, that the present "'tank''' grain elevator, now so universally used, might readily he moditied in such a way as to make the method suggested by Clement (juite practicable. TlIK NKOKS.SITY FOR THOKOIKJHLY CURING AND DRYING SEEDS. In addition to being well matured and carefully harvested, seeds should be thoroughly cuj'ed and dried before ])eing put into the stor- age bins. Much better i-esults would ha o])tained if such seeds were artificially dried for several days in a current of dry air at a tempera- ture not to exceed 35 ' C. With this method of drying, from 2 to 4 per cent of the moisture usually present in air-dried seeds is expelled. The accompanying contraction of the seed coats makes them more impervious to the action of moisture, and consecpiently the seeds are better prepared for storing and shipping. Experiments made with cabbage, lettuce, onion, and tomato seeds gave results as follows: The average loss in weight of the air-dried seeds, after an additional dry- ing of 30 days at a temperature of 30 ' to 32 ' C. was 2.7l> per cent. Yet these same seeds, when kept for 40 da^^s in the laboratory, reab- sorbed onl}' an average of O.'Jl per cent of moisture. Like ([uantities from the original sample gave only the slight variations ordinarily met with, due to the lumiidity of the atmosphere. Thus seeds, when once carefully and thoroughly dried, will not regain their original weight, provided they l)e kept in a dry room. « Nature, 1S95, 52: 544-545, 4<) THE VITALITY AND GERMINATION OF SEEDS. CHARACTER OE TJIE SEED WAREHOUSE OR STORACE IIOOM. Another important factor in the storing of seeds is the character of the seed warehouse or storage room. The hrst point to l)e considered is dryness. Such houses should l)c kei)t as dry as possi})le, wliicli can be accomplished either by means of artificial heat or I)}' the use of strong dr3'ing agents, or better still, by both. True, if the seed ware- house be located in a section having a dry climate, this difficulty is at once largely overcome. But in many cases such a location is imprac- ticable or even impossible, and other means must ])e resorted to. As a matter of fact, most large seed warehouses are not heated and a great loss in vitality inevitably follows; but each seedsman nmst determine for himself whether or not this loss is sufficiently great to justify the expense of heating such a storage room. Experiments carried on during the progress of this work have shown some very marked differences in favor of seeds stored in rooms artilicially heated. The averages of the thirteen samples of seeds from the eight places at which they were stored show a diti'erence in the loss of vitality of i>.87 per cent. Those kept in rooms that were arti- ficially heated during a greater portion of the time deteriorated 25.01 ])er cent, while those stored in rooms not so heated deteriorated 35.78 per cent. The loss here given for seeds stored in dry rooms is greater than such conditions warrant, owing to the very unfavorable condi- tions at Mobile, Ala., and Baton Kouge, La. At Lake Cit}', Fla., the relative percentages of deterioration were 29,-1:2 and 1(5.27 for the unheated and heated rooms, respectively, at Auburn, Ala., 33. IH) and 10.34 per cent, and at Durham, N. H., 39.58 and 3.57 per cent, respec- tively. Unfortimately these experiments were not made with this definite point in view, and the results are not entirely satisfactory', as no records were made of the temperatures and humidities. THE VALUE OF (JOOD SEED TO THE MARKET GARDENER. This work was undertaken chiefly for the purpose of finding some improved methods of shipping and storing seeds in small packages, wherein their vitality might be better preserved. The rapid deterio- ration in vitality causes great losses to gardeners living in districts whei'c the climatic conditions bring about the premature destruction of vitality in seeds. In many cases the seeds are practically worthless or altogether fail to germinate after a few weeks' exposure. The loss in such cases is not in the greater quantity of seed required, but the retardation or complete failure of the germination often means dela}^ making the difl'erence between success and failure in the desired crop. Seed of low vitality is even worse than dead seed. With the latter the difKculty is soon discovered, while with the former, although the seed will germinate, the seedlings are not sufficiently vigorous to develop COMFAKISON OF MP:THUL)S OK STOKINU AND yiUPriNG. 47 into stroiii;' and healthy phints. True, most eiiter])i'isinij;- oaicleners usually hu\ t> \ itality tests made immediately pi'ei)arat()iT to plautiut^', but this is not always convenient, and they rely on the residts of tests made at some earlier date. In such cases it quiti; fre([uently happens that tlu'V accept the results of tests made several weeks earlier. With n)any seeds this will suftice, yet there ai'c many others that will dete- riorate very materially within a few weeks or ev(m within a few dti^'s in such unfavorable climates as exist, for example, near the (Julf of Mexico. In a letter dated January 15, li>()o, Mr. J. Steckler, of New Orleans, La., wrote as follows concerning" the vitality of seeds: Some iset'dH lire not worth l>ciii.ir I'l'i'itrd afttT lieiii.!,' lieTi- Illicit iiioiitlis. 'I'lii.s in especially true of cauliflower j^eed. We havenuule reju-ated Icsls and this seed after reuiaining here IK) dayn was worthless and had t(j be thrown away. SI1II'1'IN(J SEKDS IN ("HAKCOAL, IMOSS, ETC. Bornt'maim" miide some ex})erinients with seeds of V'n-toi'in rafia and Juiri/ale fci'iKr, in which he found that when packed in powdered charcoal they soon lost their vitality, but when packed in powdered chalk sliolitly t)etter results were obttiined. On the other hand, Dannner* reconunends powdered charcoal as a method of packini^- for seeds that lose their vitality during- shipment, especiallv the seeds of palms and a numl)er of the conifers. Charcoal is undoubtedly much blotter than moist eartli or mt)ss. which arc fre(iuently used, the latter ati'ordino al)undant opporturiities for the develo])ment of molds and bacteria durino- transit. Some such method as moist charcoal is necessary in case of seeds which lose tlieir vitality on becomino- dr}'. Numerous other reports have ])een pul)lished from time to time concernino- the shippino- of seeds of aipiatic i)hints, tis well as those of low vitality, but they need not be discussed further at this time. NATURE OF THE KXrERIMENTS. Aside from some ])opular accounts and miscellaneous suggestions, but little has been done toward tindino- improved methods of shipping and storing- seeds of our common plants of the garden and field. Accordingly', in February, 1900, a scries of experiments was under- taken to determine some of these factors, in Avhich three (Questions were considered: (1) How may small quantities of seeds be put up so as to retain a maximum germinative energy for the greatest length of time? (2) What inmiediate external conditions are best suited for the longevity of seeds ^ (3) What part do climatic conditions play in alf ectiug the life of seeds 'i « Gartenflora, 35. Jahrg., 188G, pj). 5;^2-534. &Ztschr. trop. Laudw., Bd. I, 1897, No. 2. 48 THE VITALITY AND GERMINATION <>E 8EED8. In order to answer the lir.st (lue.stion, du[)licatc samples of the various kinds of seeds were put up in double nuinila eoin envelopes, as descri))ed on paoe 14. Likewise, duplieate sann)les were put up in small bottles, the bottles l)eing closed w^ith good cork stoppers. Some of the bottles were tilled with seed, while others were only partly full. In some cases there was a surplus air space live times as oreat as the volume of the inclosed seeds. This space, however, had no bearing on the vitality of the seeds as far as could )>e determined. In order to determine what immediate external conditions play an important part in the destruction of vitality, samples of seed, ])repared as above described, were stored in dilierent places." At each place they w^ere subjected to three different conditions of storage, which, for convenience, have ])een designated as '"trade conditions," "dr}' room," and ''basement,*''' as described on page l-t. In addition to these three methods of storage, numerous other conditions were tried in and near the lab(^ratory ; such as in incubators at increased temperatures and with varying degrees of moisture, in cold storage, in greenhouses, and in various gases, in vacuo, in liquids, etc. The third question, '" What part do climatic conditions play in affect- ing the life of seeds?" has been answered for the most part in a dis- cussion on the effect of climate on vitalit}^ page 13. In fact, the seeds in the envelopes kept under trade conditions were the same in both cases, being used here simply as a means for (^omparing the vitality of seeds when stored in paper packages and in ])ottles, as well as to show the relative merits of trade conditions, dry rooms, and basements as storage places for seeds. DISPOSITION OF THE SAMPLES. '' A more definite description of the treatment given the seeds in the various places may be summed up as follows: K(/) Jt/(u/, P. R. — The seeds were sent to San Juan on February 9, IIXX), and were returned on June 20, 1900, after a lapse of 181 days.'' At San Juan the seeds were stored under trade conditions only, and the various packages were not removed from the original 1)Ox in which they were sent. While in San Juan the l)ox containing the seeds was kept in a room well exposed to climatic influences, being protected only from the direct rays of the sun and from rain. « San Juan, 1*. E. ; T^ake City, Fla. ; Mo))ile, Ala. ; Aul)urn, Ala. ; IJatun Rouge, La. ; Wagoner, Inil. T. ; Durham, N. IL, and Ann Arbor, Mich. ^ The places of storage represented by trade conditions have already been dei-^crihed for each of the localities, but it seems advisable to rewrite the descriptions here so that they may be more readily compared with the dry room and Inisenient conditions. <-"The exact time that the seeds remained at San Juan was much less than 131 days, the time of transportation being included, as has been done for the other places. (^OMrAKlSoN OK METHODS OF STOKINO AND SHIPPING. 49 Lake C'ltij^ Flit. — The seeds were sent to Liikr City on Fehnuiry 1», l!H)(>. The tirst complete set was returned on ,Iune IS, after 121» (hiys. The second complete set was returned October 1, after 284 days. The "" trade conditions '' at Lake City were supplied hy keeping;- the .seeds in a small, one-story frame building, the dooi'sof which were open the o-reater part of the time. This building was not heated, and the seeds were stored approximately 5 feet from the ground. *' Dry room" conditions were those of a storage room on the fourth lloor of the main building of the Florida Agi'icultural C'ollegc. Tiic third set was kept in a small bulletin room in the basement of the same building. 2Iohlle, Al((. — The seeds were sent to Mot)ile on lu'bruary IT, l'.H)(». One set was received in return on fluly 7, after ISO dtiys. The other set was received on November (!, after 2()2 days. The ''ti'ade condi- tions'' in this case consisted of a comparatively open attic in a one-story frame dwelling. The set in a '"'dry roonr' was kept in a kitchen on a shelf 5 feet from the Hoor, and not more than t! f(H't distant from the stove. Here they were subjected lo the action of arti ticial heat through- out the entire period." The seeds under ''basement'' conditions were kept in a small cellar, which during the season of IIKK) was very moist. Aahuni, Ala. — The seeds were sent to Aul>urn on February 17, loot). The first complete set was received in return on May 30, the sei'ond on Noveml)er 1!) of the same year, or after 1(»2 and 275 days, respectively. ''Trade conditions '' consisted of an oilice room coimected with a gre(Mihouse, with the doors freciuently standing open; "dry room" conditions were obtained in the culture room of the biological lal)oratory on the third floor of the main building of the Alabama Polytechnic Institute, "basement'"' conditions being found in the base- ment of the same building, a comparatively cool situation, yet with a relatively high degree of humidit3^ Baton Romje^ La. — The seeds were sent to Baton Rouge on February 17, 1900. On June IS the tirst complete set was received in return. The second set remained until October 22, making the time of absence 121 days for the first and 247 for the second set. "Trade conditions" at Baton Rouge were furnished l)y keeping the seeds throughout the entire time of the experiment on shelves in a grocery store, the doors of which were not closed except at night. These conditions were thus identical with those to which seeds are subjected when placed on sale in small stores. The "dry room" was a class room on the second floor in one of the college bidldings. A storeroom in the l)asement of a private residence, having two sides Availed with brick, furnished "basement" conditioiis. «Presmnal)ly these were iu a dry i)lace, but further evidence showed that the pre- sumption was erroneous. The vajiors arisinji while eooking was being done on the stove gave rise to conditions very detrimental to a prolonged lifci of the seeds. 25037— No. 58—04 4 50 THE VITALITY AND GERMINATION <)F SEEDS. W(i(jo)U'i\ Lid. T. — The ycedt? were sent to Wagoiier uii February 17, 1900. The lirst series was received in return on June 23, after 126 days; the second set was returned after 238 days, on Octo])er 13, 1000. The sets for *■ ' trade conditions " were kept in a drug store, on a counter near an open door. The "dry room'' was a sleeping room on the first floor of the same building, while ''basement" conditions were supplied by keeping the seeds in a large depository vault in a bank. DuTliaiii., N. 11. — The two sets of seeds were sent to Durham on February 17, 1900, and were returned on July 14 and October 20, after 117 and 231 days, respectively. The seeds under "trade conditions" were kept over a door at the entrance of one of the college buikliugs. The door opened into a hall, which led into office rooms, the chemical laboratory, and the basement. An oifice room on the first floor of the same building supplied "dry room" conditions. The seeds were located well toward the top of the room, which was heated with steam and remained quite dry at all times. The "basement" conditions were found in a storage room in one corner of the basement of the same building. Ann Arhoi'., 3fich. — The set of samples placed under "trade condi- tions" was kept in the botanical lal)oratory, l)eing moved about from time to time in order to supply the necessary variations to an herbarium room, to an open window, and to an attic. From February IS, 1900, until Ma}' 12, 1900, the set of seeds under "diyroom" conditions was stored in a furnace room. The seeds were only a few feet from the furnace and were always quite dry and warm: The maximum tem- perature recorded was iS'-" C, with a mean of 38-' during cold weather, and of 30'^' C. during milder weather. On May 12 this set of seeds was transferred to the herbarium room on the fourth floor of the botanical lal)oratory, where they remained until vitality tests were made. " Basement" conditions were found in a fruit cellar, having two outside walls and a temperature fluctuating between 10*-^ and 13'- C. These packages and bottles were all securely packed in new cedar boxes from which they were not removed until after their return to the laboratory. RESULTS OF THE (4EKMINATION TESTS. After receipt of the seeds, germination tests were made as rapidly as possible, the results of which are given in the tabulations which follow. Likewise, in each case is shown the vitality of the control sample. Furthermore, a summary' of each table is given, showing the average percentages of germination of the seed from the various places for the first and second tests, respectivel}^ From these results the average percentage of loss in ^'itality has been calculated, reckoning the germination of the control sample as a standard. It is thus a verj^ simple matter to compare the relative merits of the diflerent methods of storing and the rob' th(\v play in promoting the longevity of seeds. COMPARISON OF METHODS OF STORING AND SHirPINCJ. 51 Table XII. — I'crcciildijc of (jcrintiKtiioii. nf honis snlijcded h> rorioas (-(jiKlitiunfi of nlordije in d[lferciil lucdlilies. [(Jerniiniition of control sample: First test, 98.7 per cent; second test, 98.7 per cent.] ige. Order of tests. Nnm- l)cr of days in storage. Percentage of germination. riace of stor. Trade con- ditions. Dry rooms. Basements. Envel- opes. Bottles. Envel- opes. Bottles. Envel- opes. Bottles. Lake City, Fla Do First.... 129 •J3I 102 110 121 217 IIJI 98 81 98 50 58 90 00 100 90 90) 82 100 78 98 100 98 98 97. 5 98 90 90 100 96 100 98 90 100 100 90 81 100 98 90 100 91 82 92 28 98 98 100 98 100 98 100 100 80 97. 9 54 98 100 Aulmrn, Ala First.... Second . First Second . First.... Second . First. . . . 97 5 Do 100 Mobile, Ala Do 100 98 98 Do 98 Do First. . . . 120 238 147 251 98 100 98 98 100 100 100 98 90 HI 91.5 100 84 100 92 98 92 98 Do 98 First Second . First 100 Do 98 92 Do 100 tage of ger- age of gain ity. [First.... [Second . (First.... jSecond . Average i)ercen mination. 128 251 93 09.50 90. 4 1 97 95. 13 09. 33 97. 1 1 97. 30 00. 99 55. GO 97. 04 98. 86 Average percen or loss in vita. 128 251 5. 78 29. 59 2. 29 1.72 3.31 29. 70 1.58 1.30 32.13 43.01 l.OG + 0.10 The beans at Mol)ile were seriously affected under all conditions except when put up in bottles and thus protected from the moist atmosphere. Those kept in bottles under "trade conditions" deteri- orated to 90 per cent, l)ut the result of the tirst test of tht^ same series indicates that some moisture passed through the cork and thsit the seeds were injured in that way. At Baton Rouge the beans retained their vitality somewhat better; but even here all those from the envelopes were practically worthless after 2-t7 days, for l)eans that germinate only 60 per cent arc of no value for planting. The "trade conditions" at Auburn, Ala., and Durham, N. H., were also very unfavora])le to the prolonged vitality of the beans. At Wagoner, Ind. T., San Juan, P. 11,, and Lake City, Fla., there was a marked deterioration, yet not suflicientl}^ great during the time g^ven to render them worthless for planting. However, it is quite evident that beans subjected to such conditions of storage would not be tit for planting the second season. A summary of the table shows that the vitality of the l)eans when kept in bottles and subjected to either of the three conditions was not interfered with. The averages show a variation of less than 2 per cent. With those kept in paper packages the results were quite dif- ferent, the advantage being slightly in favor of the "trade condi- tions." The loss in vitality was 2\>.r)9, 29.70, and IS.fil per cent, respectively, for "trade conditions," "dry rooms," and "basements." 52 THE VJTALITY AND GERMINATION OF SEEDS. Table XIII. — I'crceidaiji' of grnnnudion of pcdK subject <( I to variuus conditions , 20.76, and i;].«)l per cent, respectively. The seeds kept in bottles deviated but very little from the .standard of the control. COMPA.RISON OF METHODS OF STOKINO AND SHirPINd. 53 Table XIV. — Prrrnilagr of (fi'rini)i. 77 33. 44 0. 80 2. 07 9.07 42. 29 + 0.80 0.22 Table XIV shows that the cahhage, like the peas, was injured to a less deofree at Mobile and Baton Rouge than the beans, ])ut even the ("abl)age seed kept in the paper packages in these cities were all ))ut killed. The average degree of injury, however, was greater in the cabl)age than in the l)eanH. In a majority of cases there was more or less deterioration in the case of this seed kept in the envelopes. Aside from those already mentioned, the trade conditions at Durham, N. H., and the basement at Lake City, F\a., should be expressly noted. The seeds kept in the l)ottles deviated l)ut little fi'om the control, while those kept in paper pacivages germinated only .5!^. 15, HI. 50, and 53.33 per cent for thi^ trade conditions, dry room, and basement — equivalent to a loss in vitality of 43.5(), 33.44, and 4i}.iill per cent, respectively. 54 THK VITALITY AND GEKMINATION OF SEEDS. Table XV. — I'lmiUagr of (jn'in'i nation of radisJt suhjcctcd to vorioux condilionx of storage in diffnrtit localities. [Gcrmin;iti Baton RoHKc, La Do First Second . First.... 78.5 75 Do Wagoner, Did. T First.... Second . First 120 23.S 147 2.'il 79 76. 5 74.5 82. 5 79. 5 84 77 85 85 70. 5 .SO. 5 63 81 68 78 62. 5 86. 5 Do 70. 5 74 Do 79 First 82. 9 Do SiK'ond . [First.... [Second . (First.... jsecond . 78. 5 AveraRe i)ercentage of gcr- ininalion. 128 2.51 74.39 60. 94 81. .56 73. 56 76. 8(; 64. 33 8. 07 18. 37 80. 5 72. 71 75. 5 59 80.91 74.07 Average percentage of loss in vitality. 128 251 11. 02 22. 67 2. 44 6. 65 3.71 9. 67 2.5. 13 3. 22 6 The results of the tests of the radish seed are very similar to those of the ('a))l)at>-e; the latter, however, showed a greater loss in vitality. As shown by the second tests, the averaj^c percentau-es of deterioration of the eal)l)age seed which was kept in the envelopes were as follows: Trade conditions, 43. 5() per cent; dr^^ room, 33.44 p(M- cent; ])asement, 42.'29 per cent, while the loss in vitality of the radish was only 22.67, 18.37, and 2.5.13 per cent, respectively. (U)MFARIS(»N OK MKTHODS OF STORTNO AND SHIIM'TNO, 55 Table X\'1. — J'l rcnihit/c of (/truiiiKilinu offdrnil sidijci-li'd in nirloim cniKJilioiiK of storage in. (lijl'i'i-i'iil locdlit'ii's. [Germination of control siini]ile: First test, .SH.H i>er cent; second test, S2 per cent.] Order of tests. Nnm- lier of days in stoVage. Percentage of germination. riace of stomK(>. Trade condi- tions. Dry rooms. Basements. Envel- opes. Bottles. Envel- opes. Bottles. Envel- opes. Bottles. Lake ( 'itv, Fla First.... Second . First.... Second . First.... Second . First Second . First Second . First Second . First.... Second . 129 102 HO 202 121 217 i:u 120 2;!s 147 2r.i 70. 5 4:i. 5 .H4.5 ;{o 5y S. 5 "1.:! 71.5 4S. 5 SI. 5 4-.) 7.S 70 SO s:i so. 5 82 70.5 S7. 5 so S2. :? S2. 5 si;. 5 S2 51. 5 52. 5 S5. 5 7'.l 7s 78 0)7. 5 83 51.5 75. 1 10.5 7S. 5 78. 5 SC) 70. 5 83. 5 0',) 80. 8 73 3 80. 5 47. 5 20.5 57. 3 , J. Do SI 5 11(1 Mohile, Ala ]>o s7 Baton Kon.i,'-e, La 1), , 82. 3 39 S:ui .Iiian, I'. 11 Do L VVai,'oner, Did. T SI S7.5 s:; 78. 5 81 SI 85. 5 .85. 5 8U 45! 5 S3. 5 78 58. 5 s" 5 J)o 84 Dnrham, N. H Do .S2. 5 87 5 Ann .\rbor Mich S3 5 Do Second . (First.... [Seconil . (First.... |Second . 71 Average percentage (>f ger- mination. 128 251 75. 10 37.31 S2. SO. S7 70. 01 53. 83 82. 4 74.71 08. 04 37.75 83. S3 75.21 Average percentage of gain or lo.ss in vitality. 12H 251 y. 72 54.5 0.84 1.38 S. 75 34. 35 1 . 08 8. 8'.» 18.32 53. 90 f 0. 03 9. 5 T!il)le XVI shows results vory siinilar to those of Tal)le XV, except that the carrot was aft'ected sliohtly more tlian the cabbaye. There was also a g-reater falliiiootl' in the case of the seeds kept in tlie bottles in dry rooms and basements. The reason for this is not very clear. Apparently it was due to some local conditions, inasmuch as it was confined chiefly to the bottles kept at Mo])ile and liaton Kouu-e. The average results of the germination tests of the se(>ds kept in packages are quite low for the carrots. Seed from trade conditions germinated 87.81 i)er cent, from basements 37.(57 per cent, and from dry rooms 53.88 per cent, with a loss in vitality of 54.5, 54.()«», and 84:.8(» per cent, respectividy. Undin* similar conditions the cabbagt* lost in vital- ity 48. 5G, 42.j}8, and 88.45 per cent, r(\sp(^ctively. 5() THE VITALITY AND (JERMINATION OF SEEDS. Table XVII. — PercpnUKjr of gtrminnfmi of " yl " sveet corn xuhjected to rnrious condi- tions of storage in different localities. [Germination of control sample: First test, 92.7 per cent; second test, 92.4 per cent.] Order of tests. Num- ber of days in storage. Percentage of germination. Place of storage. Trade condi- tions. Dry rooms. Basements. Envel- opes. Bottles. Envel- opes. Bottles. Envel- opes. Bottles. Lake Cilv, Fla Do " First Second . First.... Second . First Second . First Second . First.... 129 234 102 27.5 140 2(')2 121 247 131 94 92 90 88 80 20 9('i 88 9r. 92 90 90 100 9fi 100 98 9G 100 98 98 100 96 94 96 94 94 98 96 92 96 86 98 94 96 94 94 80 26 96 88 92 90 9S 90 96 100 88 96 88 54.5 100 80 94.1 86 14 98 100 Au))urn, .Ma Do 92 100 Mobile, .Via Do 96 96 Baton I{(Wge, La Do 100 100 Do Wagoner Ind. T First.... 126 238 147 251 94 95. 9 96 94 100 96 96 90 96 89 96 96 92 100 100 100 92 96 Do 94 First.... Second . First 96 Do 98 96 Do Second . 98 1 First.... [Second . [First.... (Second . Average percentage of ger- mination. 12,S 251 94.75 83 94. 75 96. 75 92. 56 83. 33 94. 14 94. 86 94.87 72.08 96. 29 98 Average percentage of gain or loss in vitality. 128 251 -1-2.21 10.11 -1-2.21 -f4.71 0.15 9.81 +0.01 4-2.66 -1-2.34 22 +3.87 + 6.06 Tablk XVIII. — Percentage of germination of '^ B" sireet corn sidgected to rarions condi- tioni< of storage in different localities. [Germination of control sample: First test, 89.3 per cent; second test, 88.5 per cent.] Order of tests. Num- ber of days in storage. Percentage of germination. Place of storage. Trade condi- tions. Dry rooms. Basements. Envel- opes. Bottles. Envel- opes. Bottles. Envel- opes. Bottles. Lake Gity, Fla First.... Second . First.... 129 234 102 275 140 262 121 247 131 86 77.1 ,ss 62 4S 12 80 .54. 2 72 78 70 78 89. 3 82 92 80 60 2 92 56 81.2 .52 82 36 72 71.7 82 76 69. 5 91 . 8 88 92 90 64 8(; 82 60 16 84 66 .s(; 38 S7. 5 51 91 • 46 76 30 86 S2 75 61 4. 5 46 Do Anbiirn, .Via ])o 84 89. 6 Mobile .Via Fir.st.... Second . 86 Do 76 Baton Konge, La Do First Second . First Second . 88 61.2 Do Wagoner, Ind. T First Second . First.... 126 238 147 2.51 90 ,S4. 2 .SI ,S8 86 88 8S .83. 6 .88 48 22 81 88 80 76 88 82 81 Do 7(; Durham, N. H 80 Do .8.S First 96 Do Second . 88 JFirst.... [Second . (First.... [Second . Average percentage of ger- mination. 128 251 78. 16 65. 41 78.31 59. 70 ,83.17 66.33 75.01 48 79 60.41 80. 55 68.40 Average percentage of loss in vitality. 12.S 251 12. 47 26. 09 12. 31 32. .55 6.87 •J5. 06 16 45. 76 11.54 31 . 74 9. 80 22. 71 COMPAIII^^ON OF METHODS OF SToKINd AND SHIl'PINO. i)i Tables XVII and XVII I ha\'o ])Con considerod togothor, siiu'(^ both have to do with the .saiiie variet}' of sweet corn. The dili'erence in the (juality of these two samples was quite marked when the seed was received. Germination tests were made January 30, 1000, arid showed J»4 per cent for the "A" and 8S per cent for the "B" c()rn. In Noveml)er, 1900, samples of seed from the same orig-inal packages were tested, giving a germination of 02.1 per cent and SS.,5 per cent for the "A" and "IV samples, respectively, as shown in the controls of the above tal)les. Thus, when two grades of corn are subjected to favoral)le conditions of storage, both are well preserved; but when subjected to unfavoralde conditions, the one of poorer quality is much more suscepti))le to injury. The "A'"' sample which was stored in envelopes in trade conditions lost 10.11 per cent, as compared with 2(>.0 per cent for the "B" sample. The "A" sample Avhich was stored in dry rooms lost only O.Sl per cent, while the "'B''"' sample lost 25.0*] per cent. In basements, the "A'' saiuple lost 2o pei- cent and the " IV sample 31.74 per cent. In both samples the corn in the packages stored in the l)asement at Mobile was so l)adly molded at the time the second tests were made that they have been omitted from th(^ table. The most interesting feature in comparing the results of these two saiuples is found in the seed which was stored in the bottles. The average results of the "A'' sampl(>s show a nuich higher percentage of germination for those from the bottles than the control, while the averages for the " B '' sample were nuich lower than the corrc^spoiul- iiig controls. The average germination of the " 15 '"' sample fi'oni the bottles was 50.7 per cent foi" the trade conditions, IS per cent for dry rooms, and (>8.1 per cent foi' l)asements, or a loss in vitality of 32.. 5;"), 15.7*), and 22.71 per cent, r(\spectively. This ditl'erence was due to two causes, first, a ditlerenct^ in the quality of tln^ seed at the ])egin- iiing of the experiment, and, secondly, the larger amount of w atcr in the second sampl(\ "I).'' The greater ((uantity of water present in th.(> seed gave rise to a more humid atmosphere after the seeds were put into the bottles, especially when su!)jected to higher temperatures than those in which the seeds had been previously stored. This is an important factor always to be borne in mind when si^eds are put up in closed receptacles; they nuistl)e well (hied if \italitv is to be pinvserved. 58 THE VITALITY AND (iKRMINATlON OF SEEDS. Table XIX. — IWenitagr of (jmninaiion nf liitiire fudiji'dnJ In riirl(.iis cotKlitioiis of storage in differmt localities. [Germination of control sample: First test, 81.6 per cent; second te.st, 92.3 percent.] Place of storage. LiikeOitv, Fla. Do ..■ Auburn, Ala ... Do Mol)ile, Ala.... Do Baton RouKe, La. Do Sun .Tnan, V. R.. Do Wagoner, Ind. T . Do Durham, N. H . Do Ann Arlxir, Mich Do Average percentage of ge mination. Average percentage of lo: in vitality. Order of tests. First. . . . Second . First.... Second . First.... Second . First.... Second . First.... Second . First.... Second . First.... Second . First Second . First... Second P^irst. . . Isccond Num- ber of days in storage. 129 234 102 275 140 262 121 247 126 238 147 2r.i 128 251 128 251 Percentage of germination. Trade conditions. Envel- opes. 80. 06 77.75 1.89 15.76 84 92 85. 5 90. 5 78 8S. 5 81.5 93. 5 76 92. 5 80. 25 93 68. 5 90 80.15 91. 12 1.77 1.29 Dry rooms. Envel- opes. 81 92. 5 88. 5 90. 5 s;!. 2i 92 84.5 89. 5 79.18 78. 33 2. 97 1.5.14 Bottles. 81.14 90.93 . 56 1.49 Basements. 68 43. 5 84. 5 . 83. 5 66. 28 65.68 IS. 78 28. 95 Bottles. 77 95.5 88. 5 90 83 91.5 76 92. 5 75.2 90. 5 72 91.5 78. 31 90.78 ~4. 03 1.65 The lottuco, has shown no very marked deviation from the controls, save tlie seeds from the packages kept at Mobile, and those which were stored in l)asements in envelopes at Baton Roiig(> and Lake City. The avin-age results of the second series of tests show a similar los.s in vitalit y of all of the seeds f r-oni the envelopes. The samples of seed from the bottles germinated practically as well as the controls. The results of the first series of tests arc not entirely satisfactory, none of the tests liaving gone to standard. The low germination of the lettuce in this series was due to inability to properly control the temperature in the germinating pans. The proper temperature for the successful germination of lettuce seed is 20" C. , while in this lirst series the ger- mination tests were unavoidably made at 26'^ to 27.5'' C. Neverthe- less, this seeming o])jection is of little consetjuence, since all of the results are directly comparable with the control. COMPARISON OF MP:TH0DS OF STORTNO AND 8H1PPIN(4. 59 Table XX. — Pirct/il(i(ji' of (jtriniiKilioii af (iii'ion siiltji'clc(J la rarlous (■(iiidilloiis of KlortKjt' ■in. different localities. [(ioniiination of control sanij)le: First test, 96.8 per cent; second test, 97 per cent.] Order of tests. Num- ber of days in storage. Perec ntage of germin ition. Place of storage. Trade condi- tions. Dry rooms. Ba.sements. Envel- opes. Bottles. Envel- opes. Bottles. Envel- opes. Bottles. Lake City, Fla First.... 129 234 102 275 110 121 247 i:?] ""■■i2.7 2:{.s 117 2,'^l 95 IC). 5 9(i 12 90 0. 5 84. 5 50 9:5. 5 21.5 9(;. 5 95 97.5 95 95. 5 9(). 5 90 94.5 91.5 93 97. 5 98 90. 5 97. 5 95 91 ; 97. 5 90 97. 5 95. 5 79 90 9(; 11.5 91 95 90 9S. 5 9S 90. 5 90.5 93. 5 ()5 SO 97 75. 5 "O' 35 97 5 Ho 97 Au))nrn, Ala, I)(i First.... Se(tond . First.... Second . First.... Second . First.... Second . First.... Second . First.... Second . F"i rst 97. 5 99 Miil)ile, Ala 99 Do "(7 5 Baton Konge, La. Do.... 90. 5 48. 5 San ,Tnan, I'. K Do Wasfoner, Jml. T 95. 5 94. 5 90 99. 5 95 97 97. 5 90 97 97 90. 5 90) 31 93 91 93 47 94 5 Di) 97 5 Durham, N. 11 Do 91.5 9S Ann Artior, M ich Do Second . [First.... ISecond . 1 First.... jsecond . 98 Averai^e iiercenta,!,'e of t;er- ininatiiin. 12S 2.M 82.19 25. 12 95. SI 90. 25 S3. 79 01 90. 21 92. 36 81. 30 33. 08 90. 04 90. 80 Average iierccnta.ueof train or loss in vitalily. 128 251 14. 20 74.11 +0.01 1.20 12. .53 37. 12 + 0. 13 4. 80 1.5.07 05. 90 -K0.87 0.33 "'Phis lesl has not Ijcen inclm" niDldcd wlien put in test. 'd in making up th(> averages inasmuch as the sei'ds were badly The onion seeds which were stored in the envelopes were veiy seri- ously affected in man,y of the places. Those from the basement at Lake City, from all of the conditions at Mobile, and from the dry room and basement at Raton Rouge were entirely killed. The seed from trade conditions at Raton Rouge germinated onl}^ 0.5 per cent. In many other cases the samples from the envelopes had become practicall}^ worthless. In only two instances was there any loss in vitality where the seeds were stored in bottles, viz, the second tests from the dry rooms and basement at Raton Rouge. These two tests have lowered the average results quite materially. If they were not included the averages would be raised to 90.91 and 97.90 per cent, respectively, instead of 92.36 and 90.86 per cent, as given in the table. The average percentages of germination of the seeds from the envelopes were very low in the second test, and were as follows: Trade conditions, 25.12 per cent; dry rooms, 61 per cent, and basements, 33.8 per cent. This represents a loss in vitality^ of 7-1.11, 87.12, and 65.9 per cent, respec- tively. Onion seed is relatively short lived, and very easily affected l)y unfavorable external conditions. For this reason onion seed should be handled with the greatest care if vitality is to l)e preserved for a maximum period. This may be done successfully l)y keeping the dnj seed in well-corked bottles, or in ;iny good moisture-proof })ackage. 60 THE VITALITY AND GERMINATION OF SEEDS, Table XXI. — I'lrrrvtagr of (jrrminatinn of jvomi/ .vih/i-ctrd to vnriovs ronditions of storage in diff'rrrnt localities. [Germination of control sample: First test, G3 per cent; second test, 53 per cent.] f)t storage. Order of tests. Num- ber of days in storage. Percentage of germination. Place Trade conditions. Dry rooms. Basements. Envel- opes. Bottles. Envel- opes. Bottles. Envel- opes. Bottles. Lake (Jity, Fla Do First.... 129 234 102 275 140 202 121 247 131 44. 5 1.5 57.5 2 3 28. 5 20 G.5 48.5 7.5 o" 53.5 16.5 63 54 08 20.5 57.5 20. 5 53 34 CO. 5 58. 5 61.5 05 00. 5 60. 5 51 45 45 22. 5 66. 5 28 2 38 .58. 5 47 62 27.5 61 25. 5 44 17 10.5 60 1 4.5 62.5 57.6 First.... Second . First.... 69.5 Do 33.5 Mobile Ma . ... .59 Do 2.5 Baton Ronse, f ^a Do First 54 2.6 San Juan, I'. R Do T First.... Second . First.... Second . First.... Wagoner, Iiid. Do 126 238 147 251 50.5 49.5 44 59. 5 62 62. 5 .59. 5 03.5 00.5 40 48. 5 40 ,S. 5 49 30. 5 50 3.5 ■59 .52. 5 Durham, N. H Do 03. 5 60 First.... Second . [First.... isecond . JFirst.... [Second . 53 Do 60. 5 xTcentage of gcr- )n. [lerci'litage of lo.ss ity. Average minati( 128 251 38.87 8 60. 12 44. 75 44.43 24.41 55. 93 40. 80 31.. 57 8.08 68. 64 38. 43 Average in vita 128 251 38.3 84.91 4.57 15.60 29. 48 .53. 97 11.23 23. 02 49. 89 84. 76 6. 92 27. 49 Taulk XX II. — Percrvtage of germination of phlox drnmmondii snhjertrd to varioupt con- ditions of storage in different localities. [Ciermination of control sample: Fir.st test, 09 per cent; second test, .53.9 per cent.] Order of tests. Num- ber of days in storage. Percentage of germination. Place of storage. Trade condi- tions. Dry rooms. Basements. Envel- opes. Bottles. Envel- opes. Bottles. Envel- opes. Bottles. LakeCitv Fla First 129 234 102 275 140 ■JIVi 121 247 131 41.5 2. 5 61.5 1 0.5 47. 5 23. 5 11.6 .50. 5 ,5.6 67 0.5 67 40 78 72. 5 .5o! 5 65 51.5 02. 6 .5,S 06 01.5 73. 5 m 74 (12. 5 66 54 02 02 13.6 0.5 43. 5 02 25. 5 03 59 74.5 6S.5 .58. 6 6S. 6 20.5 05. 6 1 0.6 77.5 Do 03 Auburn, Ala First Second . First 07. 6 Do 06 Mobile, Ala .5,8.6 48 6 First.... Second . First Second . 70. 5 Do 01.6 Do First.... Sec(md . First.... 120 238 147 251 61 62. 6 33 75. 5 65 70 4.5. 6 ^.^0. 5 09. 5 .58. 6 65 9.6 09. 6 45. 6 04. 6 10. 5 75 Do 47. 6 71.6 70 First.... 72 Do Second . 01 [First.... [Second . [First.... [second . Average percentage of ger- mination. 128 251 44.87 7.62 68.31 68. 37 52. 76 17.91 63. 28 49.64 41.07 11.08 70. 35 59.6 Average percentage of gain or lo.ss in vitality. 12S 251 3t. 97 85. SO 1 + .S.27 23. 54 00. 78 8. 29 7.91 40. 49 79.46 + 2.01 -1-10.39 OOMPARISON OF MKTH(>DS OF 8TOKlN<} AND BHIPriNG. 61 Pansy iuul phlox have hocii considered to<;ether, siiiee their ])ehav- ior was ahiiost tlie same. Botli of the controls deteriorated to a con- siderable decree during- the V2r> days which elapsed between the time of the lirst and the second test, pansy losino- 15,87 per cent and phlox 21.88 per cent. In both cases the mean loss in vitality of the seeds in the envelopes was very o-i-eat. The results of the second tests show a loss of 84.91 per cent for pansy, and 85.86 per cent for phlox where stored under trade conditions. In dry rooms there was a mean loss of 53.57 per cent for pansy and t!().78 per cent for phlox, and in base- ments a loss of 81. 7() per cent for the pansy and 79.15 per cent for the phlox. These results are obtained l)y considering" the second test of the control as a standard, the depreciation of the control l)eino- dis- reoarded. Some samples were dead and many more were of no eco- nomic value. It is especially interesting- to note how (luickly the seeds died at Mobile, Ala., there bein^- only a few g-erminable seeds at the end of 110 days. The behavior of the seeds in the bottles was more or less varitible. Some of the pansy seeds showed a hig'her vitality than the control, ])ut the averages were somewhat lower, the mean loss ranging frwn 15,60 per cent under trade conditions to 27.1:9 per cent in basements, wdiile with the phlox the means for trade conditions and for basements were higher than the control ])y 8.27 and 10.39 per cent, respectively. Table XXIII. — Fercenhujcs <>/ (/cniiiudllon. of tomato Kuhjectcd to rorions conditions of doriuje in, (liji'crod loadittcs. [Geriniriiition of control siimple: First test, 95.5 i>er cent; second test, y7.5 per cent.] Order of tests. Num- ber of days in storage. I'ercentage ol germ in ition. I'lace of storage. Trade condi- tions. Dry rooms. Basements. Envel- opes. Bottles. Envel- opes. Bottles. Envel- opes. Bottles. Lake City, Flu Do First.... Second 12'J 234 102 275 14t) 2('i2 121 247 131 12(5 117 147 251 94 94 95 >)4 90 79.5 91.5 9G 94 96.5 96.5 94 94.5 87 89 98.5 94 98 94.5 98. 5 94.5 97. 5 95 96. 5 91.5 94 5 97 98 95 9.S 94 98 94 91 93. 5 97 91.5 ,S7 91 93 95. 5 97. 5 97. 5 91. 5 96. 5 95. 5 95 98 88. 5 77 96 98 64.5 19.5 .S3. 5 39. 5 94 97.5 Auburn, Ala First Second . First 94.5 Do 96.5 Mobile, Ala Do 93.5 98 Baton Rouge, La First 95 Do 96 San .Tuan I' K ' . First Do Wagoner, Ind. T Do First.... Seccind . Fir.'^t Second . First 9S 97 97 93 98 96. 5 97. 5 91 99 91.5 97.5 98. 5 9.S. 5 97. 5 97.5 89 95 96 93. 5 Durham, N. H 96. 5 Do 97 92. 5 Do Second . [First.... [Second . jFirst.... [Second . 98 Average percentage of ger- mination. 128 251 93.06 92. 44 94.81 97. 31 84 94.33 95. 21 97.07 88.21 84. 25 94.57 97. 21 Average percentage of loss in vitality. 128 251 2. 56 5.20 0.72 0.20 1.57 3.29 0.30 0.44 7.64 13.63 0.98 0.30 62 THE VITALITY AND GERMINATION OF SEEDS. The tomato need, a.s .shown in Tables V and XXV, was the most resistant to the nnfavorable conditions of storage. The seed in the bottles was not injured at any of the places. The lowest germination was 91.5 per cent from the seed kept in a dry room at Ann Arbor, Mich. The seed in the envelopes gave a much wider variation, falling quite low in some of the samples which were stored in the basements. The average losses in vitality for the entire series of the second set of seeds which were kept in envelopes were as follows: Trade conditions, 5.20 per cent; dry rooms, 3.29 per cent; basements, 13.68 per cent. The average percentage of germination of the seed which was kept in th(; bottles differed from the control less than one-half of 1 per cent. T.u;lk XXIV. — Pcrmitiujc of (jermination of watermelon subjeclcd to various cunditions (f storage in different localities. [CiLTiniii.-iticiu i)f I'ontrol sample: First test, 95.5 per cent; second test, 99 per cent.] I'liiee of .storage. Order of tests. Num- ber of days in storage. Percentage of germination. Trade condi- tions. Envel- opes. Bottles. Envel- opes. Bottles. Basements. Eiivel- Bottles. Lake City, Fla . Do .-■ Auliuni, Ala . .. Do Mobile Ala Do Baton Rouge, La. Do San .Juan, P. K Do Wagoner, lud. T. Do Durliam, N. H ... Do Ann .Vrbor, Mi<-li Do First.... Second . First Second . First Second . First Second . First.... Second . First.... Second . First Second . First.... Second . 129 234 102 275 110 2ti2 121 247 12tl 238 147 251 98 92 94 80 98 64 100 92 90 88 98 94 98 82 100 96 Average percentage of ger- (First mination. (Second . Average i>ecentage of h in vitality. 128 251 97. 75 86. 75 (First... Iseeoud 128 251 0.56 12. 37 98 96. 2 94 100 98 96 98 98 100 100 98 98 98 9(! 100 100 98 98 98 98 100 96 100 100 100 94 100 96 100 100 98 100 100 98 94 96 100 96 96 88 98 94.1 98 100 98 98. 02 96. 86 88.67 98. 29 9(i 95. 29 77.70 98. 29 97.43 0.31 0.99 1.47 10.44 0.01 3.03 3.06 21.52 0.01 1.59 What has been said of the tomato seed is practically true for the watermelon, save that there was a greater loss in vitality in the latter, when seeds were kept in envelopes. The average percentage of ger- mination of the second tests was 86.75 per cent for trade conditions; S8.67 per cent for dry rooms; and 77.7 per cent for basements, or a loss in vitality of 12.37, 10.44 and 21.52 percent, respectively, as com- pared with tlie vitality of the control sample, which germinated 99 per cent. An examination of the foregoing set of tables will show that in most cases the deterioration was comparatively slight during the first 128 days. Yet even during this short period the losses in vitality were veiy marked in some of the more critical localities, particularly COMPARISON (>K METHODS OF STOlUNG AND SHIPPING. (^3 vA l\I()l)ilo. Ilowi^vcr, the urctitrst loss, as show n hy the ocrmiiiatioii tests, was durino- the VSd days iimiiediatcly t'ollowiiii;-. While seeds, like other living- thinos, are capable of withstanditio- (piite unfavorable condilions for a consideral)le time without showiuo- any apprecial)lo deterioration in vitality, still the forces destroying vitality are at work. When the turning' point is once reached and can be detected by germination tests, the decline is more noticeable and death soon follows. The preceding tables show that the loss in vitality was very diti'er- ent in the diti'erent places. The conditions at Mobile, Ala., i)roved to be the most injurious, while those at Ann Arbor, Mich., were the most conducive to longevity. These results, however, are given in another part of this paper dealing with the etl'ect of clim;ite on the vitality of seeds. The r(^.svdts are tabulated on i)ages iS and )i>) and represented diagraumiatically on page 24, so th:it any further discus- sion at this time is unnecessary. Likewise each table has been summarized, giving the average per- centages of germination and the average percentages of the loss in vitalitv of each sample of seed for both the first and second tests. These averages include those of the three conditions of storage — trade conditions, dry rooms, and l)asements — in l)oth envelopes and Ixjttles. Naturally, the results of the second tests ai'c of the greater impor- tance, and, in order that the results may be readily compared and more critically examined, th(\v have been collected and tabulated herewith: Table XXV. — ArirtKjc iK'vcc)it(((jf per cent; l)asements, 41^.28 per cent. From these results it is (|uite clear that seeds put up in paper packages will retain their vitality much better if kept in dry, artilicially heated rooms than if they are sul)jected to trade conditions or stored in basements. But another comparison needs yet to be made, and is the most impor- tant of the series, i. e., the vitality of seeds when kept in closely corked bottles. In the majority of cases there was ])ut little deviation from the control samples, and many of the samples germinated even better where the seeds were kept in bottles. The " xi "sweet corn oU'ers the best illustration of the increased gerndnation. At the same time the " B" sample of sweet corn was very much injured. Here are two samples of the same variety of corn behaving very ditierently when kept in bottles. This difl'erence in vitality is directly attributed to the greater (piantity of water in sample '' B," showing the necessity of thoroughly drying seeds if they are to be put u}) in closed vessels. A comparison of the general averages of the bottle samples and of those kept in envelopes indicates that the former is far superior to the latter as a method for prescrNing the vitality of seeds. Under trade conditions the loss in vitality was 80.63 per cent in envelopes and EXPERIMENTS IN KEEl'lNG AND HHIPriNG. 65 3.J»8 per cent in bottlos; in dry rooms, 21. H» percent in envelopes unci S.(»s p(>r cent in bottU^s; in Imseiiionts, -1:2. 2S per cent in envelopes and 4. 51 per cent in bottles. The necessary precautions to be taken, if seeds arc to be stored in bottles, are (1) a well-dried sample, preferal^ly ai'titicially dried seed, and (2) a cool place for storino-, at least a place in which the tempera- ture will not be liig-her than the temperature at which the seeds were orig-inally dried. If the aljove precautions arc taken at least two beneficial I'esults will follow: First, protection against moisture, which is of considerable importance, as man}^ seeds are soon destroyed in that way when kept in paper packages. Secondly, vitality will })e preserved for a longer period and conse([uently there will be a more vigorous germination, a better growth of seedlings, and a greater uniformity in the resulting crop. Having thus shown that seeds retain their \'itality in warm, moist climates nuu-h 1 tetter when kept in bottles than when kept in paper packages, the necessity of finding a more suitable method for sending small (juantities of seed to such places at once presents itself. EXPERIMENTS IN KEEPING AND SHIPPING SEEDS IN SPECIAL PACKAGES. At present the greatest disadvantages in sending out seeds in bottles are the inconvenicMice and expense involved ))y this method of putting up seeds. The increased cost of ])ottles, as compared with the paper packets now so universally emplo3"ed, the additional la))or and expense necessary to put up the seeds, the greater cost in handling- and pack- ing the bottles to insui'c against losses by l)reakagc, and the increased cost of ti'ansportation, are all matters of vital imjxtrtance. Seedsmen claim that the existing conditions of the trade will not admit of their raising the price of seeds sufficiently high to justify the increased expense of glass containers. Although to the seedsmen the preserva- tion or the prolongation of vitality is an important factor, yet the demand is for an inexpensive and at the same time a neat and service- able package. Accordingly, duplicate samples of the following-named seeds were put up in special packages, one set being sent to Mobile, Ala., and the other kept at Ann Arbor, Mich. The seeds used for these experi- ments were beans, peas, cabbage, lettuce, onion, pans}', and phlox." «The lettuce, onion, pansy, and phlox were from the game bulk samples of seeds as those used in the earlier experiments; but the beans, peas, and calibage used for these tests were from samples received at the laboratory on February 4, 1901. How- ever, the latter three were from the same general stock of seed, differing from those used in exi^eriments already given only in that they were stored during the interval in the warehouse of D. M. Ferry & Co., Detroit, Mich., instead of in the botanical laboratory at the university. 25037— No. 58—04 5 66 THE VITALITY AND GERMINATION OF SEEDS. All of those samples were first dried for ten days in an iiicu])ator main- tained at a temperature of from 30 to 32 " C. The amount of mois- ture in the samples before and after clryinji;-, as well as the moisture expelled during the drying- process, Avas as follows: 3Ioiiitvrc test of needs In sprrkil p' a germination of 13.5 per ceut and 89 per cent, respectively, after sixty- one and one-half hours. Not only Avas there a marked retardation, but likewise a reduction in the final percentage of germination, with the single exception of the cabbage. These results can be more care- fully studied in Tahle XX Vi. Germination tests were made of all of the other samples on .Tune 3, 1901. the date when the seeds were returned from iNIohile. At this time the seeds in the luiprotected envelopes in the moist chanil)er were so badly molded that no germination tests wore made. Tlu^ samples from Mol)ile, wdiich were directly comparal^le with the al)ove, except that thev had been stored in a l)asement, were greatly injured. The l)eans had deteriorated to 88 per cent, the onion to 27 per cent, the pansy to 8 per cent, while the phlox was dead. However, se(>d of the other species — cabbage, lettuce, and peas — gave final p(^rcentages of germi- nation varying but little from the control, l)ut the slowing down in the rapidity of germination was sufficiently marked to show a corre- sponding loss in vitality. With the samples which were i)ut up in bottles, tin cans, and paraffined packages the results were quite difierent from those given al)ove. In no case was there any marked deviation beyond that which might be justly attributed to ordinary variation, except in the phlox from a tin can which had ))een stored in the moist chain I xu' in the laboratory. This sample of phlox germinated only 3.5 per ceut. Unfortunately, ])oth the pansy and the phlox seeds used for these experiments were not vei-y satisfactory. These samples wow at this time nearly two years old and consequently of a low vitality. The tabulated results of the foregoing experiment folloAV. 68 THE VITALITY AND GEKMINATION OF SEEDS. T A KLio X X \' I . — I 'ilnlltij of seeds jire 'I in. (Jiffrrent kinds of jmckagcs. Dura- ion of ■xperi- nient. Percent ige of germination Trc.'.'ituiont of Manii>l<'s. Beatis. Cab- bage. Let- tuce. On- ions. Peas. Pan- sy. Phlox. Aver- ages. Control Pays. 94. 90. 2 89. 5 97.5 90. 37.7 42. 5 77 34 Ann Arbor, Midi., moist chambor: Envelopes ■27 80.0 91.0 70.5 90.0 .SS. 25. 0.0 (U.35 108 108 108 98.0 97.5 96.0 91.5 93.5 87.0 91.0 90.5 90.0 93.5 95.5 93.0 91. 90.0 90.0 36. 39.5 35. 31.0 39.0 3.5 76.43 77.93 Tin can, paraflined 70. 63 Two envelopes, outer paraflinod 108 98.0 91.5 91.5 97.0 92.0 33. 5 27. 5 75.85 Two envelopes, inner paratflned 108 98.0 94.0 89. 93. 88.0 21.0 47.0 76. 14 Two envelopes, both paraffined 108 96. 90. 5 S(i. 5 95. 5 92. 23. 38. 5 74.57 Two envelopes, both i>araffined and immersed in water 27 100.0 8.S. 5 88.5 91. 5 90. 31. 5 30.5 75 21 Mobile, Ala., basement: 108 8.S. 8(). 88.0 27.0 96. 8 56.14 Bottle, corked 108 lOS 108 98.0 98. 9Ci. 91.0 90.5 88.0 90.5 92.5 95.0 95. 5 95. 5 96.0 81.0 92. 88.0 34. 5 34.5 26. 32. 5 44.5 23.0 75. 14 • Bottle, paraffined 78 21 Tin can, paraffined 73. 14 Two envelopes, outer paraffined 108 91. 90.5 89. 95.5 92.0 29. 5 34.0 74.73 Two envelopes, inner paraffined 108 90. 92.0 88.0 90.0 98.0 33.0 38.0 76. 43 Two envelopes, both 7>arafflned 108 100.0 92. 89. 5 88. 5 90. 25. 5 33. 5 74.14 Subsequent experimentw were made, using envelopes of diiierent qujilities, as well as Aaiying- the treatment of the packages. Samples of cabbage, lettuce, and onion seed were put up as follows: (a) The regular seedsmen's envelope, made of a heavy grade of manila paper. (/») Envelopes made of a medium (jualit}' of Avaterproof paper. {(') Envelopes made of a thin i)archment i)aper. (d) Envelopes made of the same quality of parchment paper as for the preceding series, ])ut paraffined previous to ])cing tilled with seed. The packages were then sealed by redipping the open ends. (e) Envelopes of parchment paper, as for the two preceding series, except that the envelopes were first filled w4th seed, sealed, and then the entire package was dipped in paraffin at a temperature of from 55^ to (50^ C. Samples of all of these packages were then stored under trade con- ditions and in dry rooms in Ann Arbor, Baton Rouge, and Mobile. The exact conditions of storage in the diii'erent places were the same as described on pages 49 and 50. The samples were put up on May 20, 1901. The period of storage ended on November 26, having continued 190 days. Unfortmiately, no special precautions were taken to dry the seeds. They were simply air-dried samples; lience they contained a quantity of moisture sufii- ciently large to give rise to an increased relative humidity of the confined air in the paraffined packages. This increased humidit}^ was EXPERIMENTS IN KEEI'ING AND SHIPPING. 69 accoinpimiod hy a greater activity within the cells, and con.scquently l)y a greater deterioration of vital force. For this reason tlu^ results are not as detinite as the conditions warrant. NcvertheU^ss, sonic ini})oi-taiit facts were brought out by the experiments which justify their being discussed and tabulated (in ])art) at this time. Taumo XX^''II. — V'lUilUii of itced prt'iiern-d In jxiruffi tied 'parka yes. Trade conditions, seeds put up in — Dry room, seeds put up in- Kind (if seed. Paraffined envelopes. Parchment envelopes, tlien dip- ped in par- affin, at 50° to 60° C. Seedsmen's packages. Paraffined envelopes. Parchment envelopes, then dip- ped in par- affin, at 50° to 00° C. Seedsmen's pacjvages. Cabbage: Ann Arbor, Mieli Moliile, Ahi Per cent. 91 HO. r> 70 .S'.t. .") so '.tl 1 Prr rent. 90 .57. 5 (■.3 K9. 5 90 i 20 Per rent. sn. 5 H. 5 'J"2. 5 90. 5 (14 74 93 Prr rent. 90. 5 :tt 73. 5 91.5 7.S ,S'J 91.5 '* Prr cent. 85. 5 .50. 5 79. 5 90 7S. 5 73. 5 S9 4. 5 40 Prr rent. SO. 5 35 5 Lettuee: Ann Arbor, Mieli Mobile, Ala 93 fil. 5 Baton RonK(\ La Onion: Ann Arbor, Midi Mobile, Ala Baton Ronge, La 72. 5 SO 59. 39 (V2. 94 i 49-14 1 fil.11 65. 66 49 22 In the first place, the injury resulting from the effect of the climatic influences i.s <|uite well marked in the above table. The conditions at Mobile and Baton Rouge were much more detrimental to the life of the seeds than were the conditions at Ann Arbor. Secondly, the dif- ferences in the preservation of vitality of those seeds stored under trade conditions and of those kept in dry rooms were much less marked than they were in earlier experiments. This is probably accounted for ])y the marked dift'erence in the two seasons. The summer of 1900 was extremely wet in the South, especially at Mobile, while the sum- mer of lOol was exceptionally' dry. Concerning the conditions Zim- mcr Brothers wrote on November 20, 1901, as follows: We do not tliink you will lind much difference in the two packactes. The season this year lias bi'en very dry, with no rain since the big August storm; in fact, we do not remember such a dry season in thirty years. Although the season was exceptionally dry at Baton Rouge and Mobile, the loss in vitality was very g-reat in comparison with the loss at Ann Arbor, demonstrating- very clearly that climatic influences play a very important part in the storage of seeds. This table shows the relative resisting powers of lettuce, cabbage, and onion seed, the lettuce being* most resistant and the onion least resistant, as shown in a preceding table. However, the chief purpose 70 THE VITALITY AND GERMINATION OF SEEDS. of this series of experiments was to demonstrate tlie relati\'e value of ditfercnt packages as a means of putting up seeds. In Table XXVII it will be o))ser\ed that the results obtained from the waterproof and parchment paper envelopes have been omitted. These omissions have been made because the results were practically identical with those of the ordinary seedsmen's packets; ])ut the com- parisons to be made l)ctween the ordinary paper packets and the parafHned packages are worthy of consideration. The envelopes that were parafHned after being tilled with sc^ed gave the best results. This difference, however, was due not to the special treatment but to the higher melting point of the paraffin. The average percentages of germination of the three samples of seed kept under trade con- ditions in the three localities were 59.39 per cent for the envelopes previously paraffined, 62.94: per cent for the envelopes dipped in paraffin after being tilled with seed, and 49.44 per cent for the seeds- men's envelopes. In dry rooms the results were 61.1 L, 65.66, and 49.22 per cent, respectively. These averages were somewhat higher than the true conditions of Baton llouge and Mobile warrant, as the results of tlie germination tests from all of the packages retained at Ann Arbor showed but little variation. Taking the three samples of seed wdiich were stoi'ed luider trade conditions in Mo))ile, the average percentage of germination was 24.2 for the seed from the nonparatlined package and 45. 5 per cent for the seed from the paraffined package, show- ing a loss in vitality of 7T.3 and 49.5 per cent, respectively, considering the germ ination of the Ann Arbor sample as a standard. At Baton liouge the results were slightly l)etter; the average percentages of germination were 32.2 for the seeds from the non])araffined and 53.5 per cent for the seeds from the paraffined packag(\s, representing a loss in vitality of 65 and 4<).5 per cent, respectively. While in either case the loss was very great, still the advantages of the paraffincnl packages arc worthy of consideration for the reason that a prolongation of life for only a few wrecks is f recjuently of the greatest importance, particularly in districts where nmch fall planting is done. In this connection may be given the results of some other tests, which reall}" were a part of this same experiment, but included only onion seed. This seed was put up in seedsmen's envelopes and in paraffined envelopes like those pri^viously described. In addition, seed was also put up in small bottles, which were corked. These packages were kept in a small l)ox within a suit case carri(>d on two trips across the Atlantic and on a tour through Central Europe, thus subjecting them to yery variable conditions. Germination tests gave the following results: Seed from the ordinarj- packages, 77 per cent; paraffined envelopes, 90 per cent; bottles, 91 per cent. To test more thoroughly the keeping qualities of seeds in paraffined packages and in l)ottles, another series of experiments was begun on Deceml)er 20, 1901. For these tests oidy cabbage and onion seeds p:xperiments in keei'in(} and snirriNo. 71 were u.sed, but each with thi'ce different deo-recs of moisture: (1) Seed from the orioinid packaoe.s, i, e., air-dried samples, the cabbage hav- ing a water content of 5.80 per cent, and the onion G.48 per cent. (2) Air-dried samples were exposed in a moist atmosphere under a bell jar for two days, during which time the cabbage absorbed 1.83 per cent of water and the onion 2.11 per cent, thus raising the water con- tent to T.<)o and 8.80 per cent, respectively. (3) Air-dried seeds which were dried in an incu])ator for eight days at a temperature vary- ing f i-om 27 C to :]',» C. During this interval 2.0,5 per cent of water was expelled from the caljbage and 3.11 per cent from the onion seed, leaving a water content of onlv 3.75 per cent in the former and 3.37 per cent in the latter. Each of the samples, treated as just descril)ed, was put up in three different kinds of packages: (1) Seedsmen's regular seed envelopes. (2) Similar envelopes which were paraffined, after being filled with seed, at a temperature of from 70'^ to 75° C. The melting point of the paraffin was 53'^ C. (3) In bottles which were closed with firm cork stoppers. One of each of the above packages was then stored at Mobile under trade conditions and in a basement; likewise at Ann Arbor in the herl)arium room of the l)otanical la])oratory, in a greenhouse, and in an incubator maintained at 40° C. The duration of this experiment was 131 days, from Deceml)er 20, 1!>(>1, to Api-il 30, 1!»02. The results of the germination tests are given in Tal)le XXVIII. Two percentages have been given for the control sample, one for Ann Arbor and the other for Mo})ile. This was necessary since the two series were tested at different times and comparisons can not be made interchangeably between the two. Tahle XXVTTI. — Yitfirily of caJihage avd onion seed rr.v prcsrrvcd iv. vdrloiis k'liids of ]i(ifka(/e.^ itnd xidijecfcd fo diffcrml eondltioiix of slorcKjc. [Genniiuitiim (if cdiitrol .'^ample.s— Ann Ar))()r: (_:abbagt', 81.7 per cent; onion, 74 per cent. Jlobilo: Cabbage, 88 i)cr cent; onion, 81.5 per eent.] Speoial treat- ment of package. Percent- age of water content of seed. Percentage of germination. Kind of seed and Ann Arbor, Mich. Mobile, Ala. package. Botan- ical labo- ratory. Tra.le condi- tion.s. (Jreen- hou.se. Incuba- tor at 40° C. Trade condi- tions. Base- ment. Cabbage: Enveloj)c None 5.8^ 5. 8U 5. 80 7. 63 7. 63 81. 80.0 79. 5 85. 5 SO. 5 81 . 79.0 85. 80. 5 82. 85.0 85. 5 84. 84. 68.0 85. 5 S5. ()5. 5 83. 5 86. 5 67.0 76.0 74.0 72. 5 62. 68. 5 74.5 69.5 48.0 73.0 71.0 64.5 60. 87. 5 81. 64.5 86.5 82.0 64.0 82. 5 82.5 10 Do Paraffin f forked 52. 5 Bottle 84. Envelope 1.5.5 Do Paraffin Corked 46 5 Bottle 7.63 80.5 3.75 76.0 3.75 i 86.0 3.75 1 83.0 91.5 Envelope Do 9.0 Paraffin Corked 78.0 Bottle 85.0 72 THE VITALITY AND GERMINATION OF SEEDS. Table XXVIII. — VltalUn of cahhar/r and onion seed as preserved i)i various ki^ids of packa(/es and snhjected to different kinds of storage — Continued. Special treat- ment of package. Percent- age of water content of .Mced. Percentage of germinatien. Ann Arbor, Mich. Mobile, Ala. jiiickagf. Botan- ical labo- ratory. Trade condi- tions. Green- house. In(nil)a- tor at 40° C. Trade condi- tions. Ba.se- ment. Onion: None G. 48 G. 4S f>. 4.S 8.89 8. 89 8. 89 3.37 3.37 3.37 78.5 7f). 5 73. .5 74. 5 74. 'i 78.0 Gl. 5 75.5 76.5 (i9. 5 OG. 5 71.5 fiO.O GG. GS. G3. 5 72.5 71.0 3.5 67.0 60.0 11.5 50. 67.5 8.5 58.0 77.0 47.0 4.5 Gl.O 28.0 9.0 3.0 •> G.O ? 9.0 59. 5 19.5 83.0 8G.0 21.0 74.5 77.5 17.0 77.0 84.5 10.0 Do Paraffin Corked None 27.0 Bottle 82.5 2 5 Do . . Paraffin Corked None 21 Bottle 78.5 Envelope G Do Bottle Paraffin Corked CO. 5 81.5 Many of the points ln-ought out l)y this tabic are veiy simihir to those of the preceding- one, 3'ct the ditierences are sutticiently marked to justify its being given in this connection. The seeds stored in the botanical laboratory and those subjected to trade conditions at Ann Arbor have g-erniinated practically the same, the cabbage slightly favoring trade conditions and the onion being better' preserved in the laboratory. But a comparison of the trabagc or lettuce after they had absor])ed tile additional amount of water. But the chief purpose of the present experiments was to determine the relative advantages of envelopes, paraffined packages, and ])ottles as methods of putting up seed in order that vitality might l)e pre- served for a longer time. This comparison is best made l)y consider- exi>p:rtmknts in Kp:EriNG and SHirriNG. 78 int^i' the vitality of the seed stored in the greenhouse at Ann Arbor and luicU'r trade eonditious at Mo])ile. It will he readily seen that the vitality of the seed from the unprotected packages was greatly reduced, while those from the paraflined envelopes and from the bottles germi- nated nearly as well as the controls. These difi'erences are bottei' rep- resented diagrainmatieally, as follo^vs: J>i(ii/rniii n jircuf'iiliiiij IIk' prrcciilnt/ca of (/irni'mation of cdhbttgc Kccd irJic^i Irralnl rifs dcsrrllx'd. Kind of package. Special treat- ment of package. Percent- age of water content of seeds. Ann Arl)or, Mich., green- hou.se. Mobile, Ala., trade conditions. 5. so fi. so 5. so 7. (« 7. (;:> 7. <;:! 8. 7r> •i. 75 3. 7ri 5. SO 78. 3 00 Do raralliiicd Corked 92. 1 s7. ."> Bottle 91.. ") s) P^nveloiir 70. 5 (i-t ."i Paraflinetl (forked Do SO. '.» Bottle 93 1 S'> Envelope 7'i 1 I rA I'arafliiied Corked Original pack- age. II r)o Sl.S S-' .S Bottle 79.7 Control sample . ss SS DUigntni rrpresenling the pcrcenUigcs^ of germinal ion of ouion seed tvhen ircided as described. Kind of Special treat- Percent- age of water content of seeds. .\nn Arbor, Midi., green- hoii.se. Mobile, Ala., trade conditions. Envelope - (i. 48 0. fS C. IS s. S9 S. so s. S9 3.37 3.37 3. 37 (!. 4S 4 7f.. r. 10 s Do .. ... S3 Corked Bottle ('iS. i\ Envelope 13. ■! 04 •)] Do Paraflined.... 74.. "> Bottle Corked 77. 3 Envelope 9.7 00. 3 17 Do Paraflined Corked Original iiack- age. ' ' Bottle ss Control sample.. S4..'-. s4.ri The percentages for Ann Arbor shown in the graphic representations are not the same as those given in the foregoing- table. In the diagram they are directly c<)mparal)le with the results from the Mobile series, 74 THE VITALITY AND GERMINATION OF REEDS. all beino- based on the vitality of the controls, as shown ])y the tests made at that time, the standard being- 88 per cent for the cal:»bag-e and 84:. 5 per cent for the onion. A discussion here hardly seems necessary, as there can l)e no doubt that seeds retain their vitality nuich better in moist climates if pro- tected from the action of the atmosphere. This ma}^ be accomplished by dipping" the packages in paraffin or ]>y putting the seed in bottles. Disregarding the expense, bottles surpass paraffined envelopes as a means for the preservation of vitality, and also in tlu^ ease with which the seed can be put up. The results are more certain if care is exer- cised in selecting good corks. RESPIRATION OF SEEDS. I'rom a practical point of view it has been conclusively sliown that moisture is the controlling factor in seed life. Seeds stored in a humid atmosphere soon lose their vitality, 1)ut if carefulb: dried and protected from moisture life is greatly prolonged. The question at once presents itself: In what Avaydoes the presence of increased ({uantities of moisture . cause a premature death of the seed, or why is vitality prolonged if the water content of the seed be reduced? In a measure, the answer to this question is re.' Carl)on dioxid 1-2 At the end of 1 years 7 months and 11 days an analysis of a sam- ple of air taken from the other chamber wiis as follows: Peas, :!.580 gramf<, in air^ in dark: Percent. Oxygen. 20. 8 Nitnjgen - 79. 1 Carl)on dioxid ^ The ;-].152 grams of peas that were subjected to tin* influence of the action of light had al^sorbed, in the given time, 2.1 cc. of oxygen and produced 1.8 cc. of carbon dioxid. The seed kept in the dark showed ))ut little signs of respiratory activity. Germination tests of the former showed the peas to be dead, while five peas from the sample kept in the dark germinated perfectly. While there is no question that light exerts some influence on respi- ration, .still the above results do not furnish sullicient data to establish the fact that respiration practically ceases in the absence of light. In fact, experiments have shown that respiration is also quite marked in ca.se of seeds stored in the dark, and the difference is very slight if the same temperature be maintained. Van Tieghem and Bonnier, in their "Recherches sur la vie latente des graines,"'' demonstrated that 7.97(3 grams of peas, sealed, in air, «Ann. Agron., 23: 433-471, 1897. 6 Bui. Soc. bot. France, 29: 25-29, 1882. 76 THE VITALITY AND fnORMINATION OF SEEDS. in a tube, re.spirod quite freely. After the lapse of two years an analysis of the eontined air yave the followino- results: I'cr cunt. Oxygen 14. 44 Nitrogen 81 . 74 Carbon ilioxid 3. 82 These same seeds germinated 45 per cent and had increased fi u of their original weight. In the experiments of the writer it was found that 40.1150 grams of air-dried beans liberated 7.7 cc. of carbon dioxid in 370 da^'s. The concentration of the carl)on dioxid in the flask at the time the gas was drawn for analysis was 1.54 per cent. This sample of seed germinated 97 per cent, and there was only a very slight retardation in germina- tion, which indicated that the vitalit}' had not been materially reduced. During this time there was a slight decrease in the weight of the seed — 0.19 per cent. At the same time two check bottles were set up, one containing 40.1184 grams of beans known to be dead, and the other bottle containing nothing except air. Analyses of the air from these two bottles gave the same results as samples of aii- drawni from the laboratory. These preparations were kept in subdued light through- out the experiment. That respiration may take place in the dark, that it is very intense if much moisture ])e present, and that intensive respiration is accom- panied b}' a rapid loss in vitality is shown by the following experi- ments. On April 3, 1900, samples of beans, cabbage, carrot, lettuce, and onion were sealed, each in bottles of 250 cc. capacity, and were stored in a dark room which was maintained at a temperature of from 20^ to 25° C. These samples were first carefully weighed and then placed in a damp cham))cr for 175 hours, so that an additional ([uantity of moisture could be absorbed. Control samples of air-dried seeds were also kept in sealed l)ottles and subjected to the same subsequent treatment. After the lapse of one year analyses of the coniined gases and germination tests of the seeds were made, the results of which are given with the general details. BeauH. — Of beans, 24.9994 grams absorbed 4.70 per cent of water while in the damp chamber. The respiration during the year was equivalent to 2.5 cc. of carbon dioxid. The loss in weight was only 0.05 per cent, but the vitality had fallen from 100 to SO per cent, as shown by the control. C(d>h'. — Of cabbage seed, 10 grams, with an additional 9.79 per cent of water, were used for this test. During the A^ear this sample of cabbage seed had given off 24 cc. of carbon dioxid, an equivalent of 2.4 cc. of carl)on dioxid per gram of seed per year. The control sample germinated S9 per cent, l>ut this seed w^as dead. KESriKATION OF SEP^DS. 77 Ciirrot. — Of ciiiTot seed, lU omnis Avcrc iillowed to !il)sorl) during lTr> hours an additional 10.25 per cent of water. In one year 27 cc. of carl)on dioxid were i)roduced, o-iyino- a concentration of carbon dioxid of nearl}" 12 per cent. The deterioration in vitalit}" was from S-1 to per cent, as compared witli tlie control. Lettuce- — Of air-dried lettuce seed, 10 f^rams were allowed to absorb an additional S.ST ])er cent of water. During' the experiment 19.5 cc. of car])on dioxid were formed, an equivalent of approximately 10 per cent of the original volume of the inclosed air. These seeds Avere all killed. The control sample germinated 04 per cent. On! oil. — Of air-dried onion seed, 10 grams were allowed to absorb an additional 10.11 per cent of water. The seed gave off 2B.5 cc. of carbon dioxid during the experiment and deteriorated in vitalit}" from 97 to per cent. A bottle containing -t cc. of water was also sealed at the same time and served as a check for the other analyses. A sample of air taken from this bottle gave the same results as the original air sample. It is a matter of much regret that no analyses could be made of the air from the bottles which contained the check samples. These bottles contained the same weight of air-dried seeds as was used for the experiments. Unfortunately the seals on these bottles had become dry and admitted of an exchange of gases, so that the results were not reliable. Another series of experiments consisted in keeping onion seeds in sealed bottles for 1 year and 13 days, with the following results: {(i) Fifty grams of air-dried seed were sealed, in air, in a bottle of 500 cc. capacity. There was an increase in the weight of the seeds of 0.1091 gram — slightly more than 0,2 per cent. An analysis of the inclosed gas gave: Pit cunt. Oxygen 12. 27 Nitrogen 8.5. 87 Carbon dioxid 1. 86 ilj) Fifty grams of air-dried seed were sealed, in air, in a 500 cc. bottle, with -1 cc. of water in a small test tube at the bottom of the l)ottle. Nearly all of the water was a})sorbed by the seeds, there being an increase in weight of 3.(3475 grams, or 7.3 per cent. The composition of the inclosed air was: Per cent. Oxygen None Nitrogen 86. 65 Carbon dioxid 13. 35 The oxygen had all ])een consumed and the seeds were all dead. (<") Fift}^ grams of onion seed were sealed in a 500 cc. bottle, in a 78 THE VITALITY AND GERMINATION OF SEEDS. mixture of illiiniiii:itiiii>- yas and air. The iuerease in weight was only 0.04 per cent. An analysis of the inclosed g-as was as follows: Per cent. Oxygen 3. 23 Car])on dioxid - . . . . 1. 21 Methane and nitrogen - - - 95. 96 {d) Another 50-grain sample of onion seed, belonging to a different series, was scaled in a l)ottle of 300 cc. capacity, and showed the following- composition of the inclosed air: Per cent. Oxygen 8. 02 Nitrogen ;. 85. 17 Carbon dioxid - 6. 81 In only one case Avas there any deterioration in vitality, namely, where the large quantit}' of moisture was present. The other samples germinated normally. The seed kept in the illuminating gas germi- nated even better than the control. In all of the bottles there was a marked decrease in pressure, show- ing that the volume of oxygen absorbed was much greater than the volume of the carbon dioxid given off. During respiration certain chemical changes must be taking place which exert a marked influence on the vitality of seeds. What these changes are is a (juestion yet to be solved. The protoplasts of the individual cells gradually but surely become disorganized. C Do Candolle" takes the view, in discussing the experiments of Van Tieg- hem and Bonnier, that during respiration life is simply subdued. But the period of subdued activity, he nays, is comparatively short, for respiration soon ceases and life becomes wholl}^ latent. As a result of his own experiments in storing seeds at low temperatures he con- cludes that seeds cease to respire and become completely inert; in which case they can sufl'er any degree of reduction in temperature without being killed. The killing of the seeds experimented with (lobelia) he attri])utes to the fact that the protoplasm had not Itecome inert, but simply subdued, and the seeds were thus affected by the low temperature. As a result of latei- experiments C. De Candolle,^ in keeping some seeds under mercury to exclude air, concludes tluit "'seeds can continue to subsist in a condition of complete vital inertia, from Avhich they recover whenever the conditions of the surrounding medium permits their 'energids,' or living masses of their cells, to respire and assim- ilate." He compares the protoplasm in latent life to an explosive mixture, having the faculty of reviving whenever the conditions are favorable. This comparison seems rather an unfortunate one; yet, within a certain measure it is probably true. "Revue Scientifique, ser. 4, 4: 321-326, 1895. &Pop. Sci. Monthly, 51: 106-111, 1897. RESPIRATION OF SP:EDS. 79 It is now ({uito <4eiicralh' iicceptod that respi ration is not absolutely necessary for Mic maintenance of seed life, notwithstanding- the fact that Gray contended that seeds would die of suifocation if air were excluded." The experiments of Gig-lioli''' in keeping seeds of Medlcago saflvd immersed in various licpiids for approximately sixteen years, after which many responded to germination tests, has done much toward demonstrating the fact that seeds can live for a considerable time in conditions prohil)iting respiration. Kochs'" succeeded in keeping seeds for many months in the vacuum of a Geisslor tube without being al)le to detect the presence of any carbon dioxid, and consequently he concluded that there was no gas given off by intramolecular respiration. Romanes'' kept various seeds in vacuum in glass tubes for 15 months and the sccmIs were not killed. However, his vitality tests can not be considered as entirely satisfactory. In the first place, the number of seeds used (ten) Avas too small; secondly, the variations in the results, even in the controls, indicate that the samples were not of very good quality. In the experiments of the writer cabbage and onion seed were kept in a \acuum over sulphuric acid for 1S2 days. During this time all of the free water had been extracted from the seed. When again con- nected with a ^•acuum gauge the dial showed that there was not the slightest change in pressure, and that consequently no evolution of gases had taken place. The cabbage germinated 75 per cent and the onion 73 per c(Mit as compared Avith 81 and 74 per cent, respectively, for the controls. The results of the various experiments above given demonstrate quite fully that the vitality of seeds, as we conuuonly know them, is not interfered with if they are ke])t in conditions pi'ohibiting respira- tion. Brown and Escombe' hold that all chemical action ceases at temperatures of liipiid air. They accordingly conclude that " any consideral)le internal chemical changes in the protoplasts are rendered impossiljle at temperatures of —ISO-" to — 19U' ' C, and that we must consequently regard the protoplasm in resting* seeds as existing in an absolutel}' inert state, devoid of any trace of luetabolic activity and 3'et conserving the potentiality of life * * * And since at such low temperatures metabolic activity is inconceivable an immortality of the individual protoplasts is conceivable providing that the low tempera- tures be maintained." «Amer. Jour, of Sci., M series, 24: 297, 1882. '^Nature, 52: 544, 1895. cBiol. Centrlil., 10: 673-686, 1890. f'Proc. Roy. Soc, 54: 335-337, 1893. y many difficulties and is likewise tilled with many sur- prises, and before the (piestion of the vitalit}- of seeds can be under- stood a more comprehensive knowledge of both the functions and composition of the cell contents is necessary. It is well known tliat all organic compounds are made u}) of a very feW' elementary substances, but the numerous and o])scure ways in which they are put together furnish questions of the greatest per- plexity. kSubstances having the same elements may diU'er widely as to their properties. IMoreover, isomeric substances — i. e., those hav- ing the same elements in the same proportions, giving an equivalent molecular weight — are usually very different in their chemical reac- tions and physiological functions. As yet this intramolecular atomic rearrangement is but vaguely understood, and the writer ventures to suggest that w ith a more comprehensive knowledge of the chemistry of the living cell some such chemical activity will be discovered. With these discoveries will come, perhaps, an understanding of the devitalization of seeds, and with it the theory of the immortalit}^ of seeds wdll vanish. SUMMARY. (1) Seeds, like other living organisms, respire when subjected to normal conditions of storage. (2) Respiration means a transformation of energy, and consecpiently a premature death of the seed. (3) W^ithin certain limits respiration is directl}^ proportional to the amovuit of w^ater present in the seeds and to the temperature at which they are stored. (4) B}' decreasing the water content of seeds respiration is reduced and vitality greatly prolonged. "Conipt. Rend., 134: 1243-1246, 1902. 25037— No. 58—04 (i 82 THK VITALITY AND GERMINATION (>K SKP]DS. (5) III most seeds tlir ([iiaiitity of oxygen ii])sor))(Ml Mn>;itly exceeds the (luaiititv of carbon dioxid evolved. (r») llespiration is nearl}" as active in the dark as in the liglit. (T) Respiration apparently is not necessar}- for the maintenance of seed life. (8) A cessation of respiration does not mean a cessation of chemical activities. ENZYMES IN SEEDS AND THE PART THEY PLAY IN THE PRESERVATION OF VITALITY. DurincT the past decade the so-called unorganized ferments have taken an important place amono- th(> sul)jects of biological research. Our knowledge of their wide distribution has increased manj^ fold. The part they play in botli ana])olisni and catal)olism has furnished us many surprises, but with all of the work that hasljeen done our knowl- edge of these most complex compounds is very limited. The part that enz3'mes pla}' in the processes of germination is of the utmost importance. It is now quite well understood that they are developed as germination progresses. They act on the most complex reserve food products, converting them into simpler substances that can be more readily utilized by the growing seedling. However, even in this connection there is a great diversity of opinion, especially as to their distribution and enzymic action within the endo- sperm itself. Puriewitsch," (Jri'iss,''' and Ilansteen'' are cited by Brown and Escom])e"' as holding the view that the amyliferous cells of the endosperm of the grasses can digest their reserve materials independ- entl}^ of any action of the embryo — i. e., the starch-bearing cells are living cells and secrete enzymes in the grasses as well as in the coty- ledonous cells of Liqy/nuK^ l^JiaseohiK, and R/clnus. In 1890, Brown and Mori'is'' did not find such to be the case; but the results of Purie- witsch, (Iruss, and Hanstecn led to a duplication of the experiments by Brown and Escoml)e in 1S98. At this time they demonstrated that the amylif(>rous cells play no part in the chemical changes which take place during the process of germination, l)ut on the contrary that the enzymic action in the endosperm of the grasses is confined to the aleuron laj'er. But the purpose of the present paper is not to consider the localiza- tion, of the particular enzyme, and nuich less the action of enzymes during germination. At this time quite another question is to be «Pringsheinis Jahrlj., 31: 1, 1897. ^'Laiidw. Jahrbiicher, 189(i, p. 385. '■Flora, 79: 419, 1894. f^Proc. Roy. Soc, 63: .3-L'5, 1898. <■ Jour. Clieiii. Soc, London, 57: 408-528, 1890. ENZYMKS IN SKEDS. 83 coiisidcriHl, \'i/., Ill w liiit way do riizyiucs rimclioii in tlic, i)r('S('rvatioii of vitality '. i\Ia({iionnc " points to the view that the vitality of seeds is dependent on the .sta})ility of the })aitieular fm-iiUMit present. Pie attributes the l)rolon<^atiouof vitality in seeds that are kept dry to the l)etter pi'eser- vatioii of the enzymes. This \iew has ])een laru-eiy strengthened as a, result of the investigations made by Thompson/^ Waugli,'' Sharpe,'' and others, in which they have shown that the artiticial use of enzymes may grcatl}' increase the percentage of germination in some old s(mkIs. By the use of diastase the percentage of germination of 12-year-okl tomato seed lias l)een increased more than GOO per cent. If the suggestions made by Ma([uenne were true in every sense, then dead seeds should be awakened into activity by artiiicially supplying the necessary enzymes; ])ut this can not be, or never has been, accom- plished. True, many experiments have Ix^en recorded in which a greater percentage of seed has been induced to germinate by the judi- cious use of conunercial enzymes than ])y the ordinary methods of germination; l)ut this treatment is applicalde only where the vital energy is simply at a low el)l) and does not in any way ati'ect dead seeds. The experiments of the Avriter with naked radicles from the embryos of living and dead beans have shown the presence of enz3^mes in both. The carefully excised radicles were ground and macerated in water for one hour. The filtrate was then added to dilute solutions of starch paste. The solutions from the living eml)ryos gave rise to an energetic h3'drolytic action. In all cases hydrolysis was sufhciently advanced to give a clear reaction with Fehling's solution. The solu- tions extracted from the radicles from the dead beans also gave reac- tions sufficiently clear to indicate that there was still some ferment present.'' However, the hydrolysis was scarcely more than l)egun, gi\ ing only a ])rown color with iodin, Init not reacting with Fehling's solution. Results of a similar character were obtained from portions of t\w, seed f'Anu. Agron. 26: 321-332, 1900; Compt. Kciid., 134: ]243-124(), 1902. & Gartenflora, 45: 344, 1896. '•Ann. Report, Vt. Agr. Exj). Stu., l.S9()-97, and Science, N. S., 6: 950-952, 1S97. ''Thirteenth Annual Report, Masn. Hatch Exp. Sta., Jan., 1901, pp. 74-83. ' This wan a sample of "Valentine" beans grown in 1897. The same year tiiey tested 97.3 per cent. In March, 1898, the same sample tested 87 i)er cent. At tliis time they were sent to Orlando, Fla., where tliey remained until May 8, 1899, aj)proximately fourteen months. The l)eans were then returned and numerous germination tests were made at irregular intervals, l)ut in no I'ase was there any indi- cation of vitality. Several samples were also treated with "Taka" diastase (solu- tions varying in strength from 2 to 10 ])er cent), hut none was stimulated into gei-mination. The radicles were tested for enzymes iu tlie spring of 1902, nearly three years after the beans lirst failetl to germinate, at which time they were nearlj' 6 years old. 84 THE VITALITY AND GERMINATION OF SEEDS. taken from the point of union of the axis and the cotyledons. These possessed stronger hydrolytic powers, the preparations from tlie living- and dead l)eans each giving clear reactions with Fehling's solution. A third series of tests was made by stopping the germination of l)eans when the radicles were from 1 to 1.5 cm. long. These were then kept quite dry for nearly seven months, after which the dessicated radicles were liroken oli" and macerated like the above. This solution was then allowed to act on starch paste, and the tratisformations wer(^ almost as rapid and complete as when a 1 per cent solution of commercial ''Taka" diastase was used. These results lead one to believe that the loss of vitality in seeds is not due to tlie disorganization of the enzymes present. There is some- thing more fundamental and probably more complex to whicli we must look for this life-giving pi'inciple. True, as Ma<[uenne has suggested, there is a close relationship between the loss of \'itality in seeds and the decom])osition of enzymes. In ordei' to determine what such a relationship might signify, the following series of experiments were made: Beans, peas, cabbage, lettuce, onion, ])]dox, and pans}^ seed, with definite quantities of good commercial "" Taka" diastase, were put up in bottles of 120 cc. capacity, as folloAVs: (1) In bottle closed with cork stopper. (2) In bottle closed w'ith cork stopper and paraffined. (8) 0.5 cc. of water in the bottle with the seeds and the diastase, the bottle sealed Avith paraffin. (4) 1 cc. of water in the bottle with the seeds and the diastase, the bottle sealed with paraffin. (5) 2 cc. of water in the bottle with the seeds and the diastase, the l)ottle sealed with paraffin. (6) 3 cc. of water in the bottle with the seeds and the diastase, the bottle sealed with paraffin. (7) 4 cc. of water in the bottle with the seeds and the diastase, the bottle sealed with paraffin. The water in each case was carefully added on small strips of tilter paper and never were the seeds or the diastase wet, only becoming gradually moist as the water was absorbed. These different preparations, each containing one of each of the sam- ples of seeds and a definite ({uantity of the dr^^ powdered diastase, were then maintained at the temperature of the laboratory for a period of 85 daj^s. At the end of that time the vitality of the seeds was deter- mined and simultaneously the hydrolytic power of the diastase was ascertained. The results of the germination tests are given in Table XXIX. The effect of the increased quantity of moisture on the diastase is given in the discussion following the table. ENZYMES IN SEEDR. 85 Table XXIX.— /.on III ritaliti/ of sif(Js ifilli viirijhK] (h't/re('.'< of inuistnrr ivIk'h kcjit (it ord'nuini room icmjicrature. [Duration of experiment. So days.] Labor- PreparatioH of siiniiilc. Amount of water added. Percentage of germination. iitory niim- l»"r. Beans. Peas. Cabbage. Onion. Plilox. Pansy. Average of all samples. ('(intnil" ... cr. None... <.»i;. 1) 90. 91 . 5 9.'). 41.25 ICi. 70. G 1547 <\,Ykr,\ None... 9.H.0 or,. . 91.0 92. 5 52. 32. 70. 9 1548 rarallUH'd .. None... 9<;.o 92. 91.5 9:5.0 39. 5 31.0 73. 8 1549 do 0.5 w;. 92. 89.0 88. 8 28. 5 2.'). 5 09.9 1550 do 1.0 yf>. .SS. 89.0 C)4.0 12. 5 18.0 01.2 1551 do •J.O 9(;.o .SC). 78. 13.0 . 5 2.5 40. 1552 do 8.0 94.0 94.0 65. 2.5 .5 .5 40. 1 1553 do 4.0 90.0 81.6 54. 5 .0 .0 .0 37.0 "The samples prei>areil. exeepting the control, were in bottles of 120 ee. eai)aeity. The above table shows that there was a gradual deterioration in vitality as the (juantit}" of water was increased. All stages of injiiiy were manifested, ])ut it is not necessary to enter into a discussion of the table at this time, inasmuch as similar tal)ulations, showiiij^" the injurious etiects of vaiying" quantities of moisure on the seeds, have already ])een given on page 38. This table is inserted here in order that a comparison can be made with the decomposition of the com- mercial diastase used and the loss in vitality of the seeds. For a determination of the diastasic activity various quantities of 1 per cent " Taka" diastase solutions were allowed to act on definite quan- tities of a 1 per cent solution of starch paste, the whole being maintained at a temperature of from W^ to 48^ C. Ten cubic centimeters of the starch solution were taken for each determination, and the amount of the diastase solution varied from one-half to 1, 2, 3, and 5 cc. In the control sample, consisting of diastase from the original bottle as it was kept in the laboratory, 2 cc. of the 1 per cent solution were sufficient to cause a complete hydrohsis of the 10 cc. of 1 per cent starch solution. In Nos. 1547, 1518, and 1519 the samples from the control bottle, the paraffined bottle, and the ])araffined bottle containing 0.5 cc. of water, respectively, 3 cc. of the diastase solution were necessary for a com- plete hydrolysis. In Nos. 1550, 1551, and 1552 — that is, the samples from the ])ottles which contained 1, 2, and 3 cc. of water, respectively — the diastase was very much injured as a result of the increased quan- tity of watei" in the bottle and 5 cc. of the diastase solution were requii-ed to hydrolyze the 10 cc. of the 1 per cent starch paste. No. 1553 — the sample from the bottle which contained the 1 cc. of water — showed that the diastase had been almost completel}" disorganized, inasmuch as the greatest quantity used (5 cc. of the 1 per cent diastase .solution) was only sufficient to cause a slight hydrolytic action. When 86 THE VITALITY AND GERMINATION OF SEEDS. tested with iodine there was still a deep, ])urplisli-l)liie color. In this last case the average percentage of gerniination had decreased to 37.6 per cent, as compared with 7«).() per cent for the control samples. Moreover, in the latter case, the onion, phlox, and pansy seeds were killed. These results show that there is a remarkable uniformity between the loss in vital it}" of seeds and the loss in the enzymic action of the "Taka" diastase under similar conditions, but it does not furnish con- clusive evidence that the loss in vitality of the seeds is in an}' way governed by the particular enzymes present. In fact, the evidence at hand better sul)stantiates the opposite view. In the first place dead seeds may still contain active ferments. Secondly, the prolonged sub- jection of seeds to the action of ether and chloroform is generally accompanied by a premature death, and if the seeds are moist the loss in vitality is uuich more marked. On the other hand, it is generally accepted that either of these gases exerts no injurious effect on the hydrolytic action of the various ferments. Townsend " has shown that the action of diastase on starch paste is even moi'e energetic in the presence than in the absence of ether, but in germination ether usually has a retarding influence. In some cases, however, growth is stimu- lated ])y the use of ether. In the third place enzymes can not l)e the chief factors controlling the vitality of a seed, because the more sensitive growing point of the radicl(> suffers injur}' much in advance of the other portions of the seed. Not inf recpiently in making germination tests do we ffnd that the growing tip of the eml)ryo is dead, while other portions of the seed may still be living and capable of carrying on all normal met- abolic process(>s. The bean is one of the l)est examples for demon- strating this fact. Here the radicle may be entirely dead, yet the cotyledons may still l)c able to make some growth; but in all seeds where the growing tip is dead the remaining portion of the radicle may be li^'ing, in which case adventitious roots may l)e formed and growth may continue for a considerable time, though very rarely will a healthy seedling l)e developed. It thus seems quite clear that the real vital elements arc closely associated with the growing point, and when this portion of the embryo is once dead the vital energy in the other parts of the seed is not of such a nature as to enable growth to con- tinue for any length of time. Even though the reserve food products are digested they can not be assimilated by the growing radicle, which should be the case were enzymes the chief elements to which the preservation of vitality is attributed. Enzymes play an important part in the vitality of seeds, and are undoul)tedly necessary for the normal development of a seedling, but the points above given show that the life of a seed is not entirely "Bot. Gaz., 1S!»V), 27: 4r>8-4()(). SUMMARY. 87 depeiidcnl on tlio, sta])ilitv of the particular fernioiit or fcnnents present. There is soniethinu- more remote, possibly of a simpler but proba])ly of a more complex composition, to which we nuist attribute the awakening- of the meta))olic processes. Reference is not made here to the zymogenic substances which (hnelop into the particular ferment, for what has ])een said of tht^ latter ap[)lies (Miually w(dl to the former. If the zymogens were pei'fectly preserve* 1 the resulting ferments would l)e developed normally and germination would continue in the usual manner. In conclusion, it ma}' well be emphasized that no single element or compound can be isolated as the sole source of vitality in seeds. There nuist be a coml)inatiou of factors, each of which plays an important role in the preservation of vitality. The desti'uction of any one of these factors may ui)set the principles go^'erning• the life of a seed, and consequently cause a premature death. It is quite probable that the nucleus is one of the most important organs governing vitalit}', for unless it continues to function no other growth can take place. Other pai-ts of the cell, however, may be of equal importance. At all events all hope of future gain nuist c(mie from more critical studies of the ccdl contents to know their chemical composition and possible reactions. A correct solution of these perplex- ing ((uestions is nothing less than a determination of the fundamental principles of life. What will ]>e the ultimate results no one is prepared to sa}'. SUMMARY. (1) A seed is a living organism, and must be dealt with as such if good results are expected when put under favorable conditions for germination. (2) The first factoi-s determining the vitality of a seed are maturity, weather conditions at the time of harvesting, and methods of harvest- ing and curing. (3) Immature seeds sown soon after gathering usually germinate readily, but if stored the}^ soon lose their vitality. On the other hand, well-matured seeds, harvested under favorable conditions, are com- parativel}^ long lived when properl}^ handled. (4) Seed harvested in damp, rainy weather is much weaker in vital- ity than seed harvested under more favoral)le conditions. Likewise, seed once injured will never regain its full vigor. (5) The curing of the various seeds is of the utmost importance, and great care should be taken to prevent excessive heating, otherwise the vitality will be greatly lowered. (6) The life period of any species of seed, granting that it has beei; thoroughly matured and properly harvested and cured, is largely dependent on environment. 88 THE VITALITY AXD GERMINATION OF SEEDS. (7) The average life of seeds, as of plants, varies greatly with diti'er- ent families, genera, or species, hut there is no relation between the longevity of plants and the via})le period of the seeds they bear. The seeds of some plants lose their vitality in a few^ weeks or months, while others remain viable for a number of years. (8) With special precautions and treatment there is no question that the^life of seeds may be gi-eatly prolonged beyond that ^\hich a\'(^ know at present, though never for centuries, as is frequently stated. Ceases so reported can not l)e taken as evidence of the longevity of seeds. (9) It is known that seeds retain their vitality much lietter in some sections of the country than in others. Tlie part which climatic influ- ences pla}^ in the vitality of seeds is of much more importance than is generally supposed. (10) Experiments have shown that mohture is the chief factor in determining the longevity of seeds as they are commercially handled. Seeds stored in dry climates retain their vitality much ])etter than when stored in places having a humid atmosphere. (11) The deleterious action of moisture is greatl}^ augmented if the temperature be increased. Not infrequently is vitality destroyed within a few weeks or months when tlie seeds are stored in warm, moist climates. If stored in a dry climate, the question of temper- ature within the normal range is of little moment. (12) The storage room for seeds as they are ordinarily handled should alwa3^s be dry. If seeds could be kept dry and at tlie same time cool, the conditions would l)e almost ideal for the preservation of vitality; but the difficulties to be overcome in order to secure a dry and cool storage room render this method impracticable. (13) The most feasible method for keeping seeds dry and thus insur- ing strong vitalit}" is to store them in well ventilated rooms kept dry by artificial heat. This method of treatment requires that the seeds be well cured and well dried before storing. (14) If seeds are not well dried vitality is ])est preserved at tempera- tures just above freezing^ provided that the temperature is maintained uniformly. (15) In no case must the temperature of the storage house be increased unless the seed is amply ventilated so that the moisture lib- erated from the seed can l)e carried off readily by the currents of warm air. If this precaution is not taken the increased humidity of the air confined between the seeds will cause a marked injury. For this same reason seeds kept at low temperatures during the winter will deterior- ate in the warm weather of spring, especially if they contain much moisture. (16) Most seeds, if flrst carefully dried, can withstand long expos- ures to a temperature of 37" C. (98.6 ' F.) without injury, but long exposures to a temperature of from 39 ' to -10' C. (102.2 to lo-l F.) SUMMARY. 89 will cause premature death. It' the seeds are kept in a moist atmos- }>iiere a temperature of even 30" C. (80 F.) will soon cause a marked injury. (IT) Seeds can endure any degree of drying without injury; that is, ))y drying- in a vacuum ovor sulphuric, acid. It is believed that such a reduction in the water content is necessary it" \itality is to be pre- served for a long jieriod of years. However, with such treatment the seed coats become wvy Hnn, and there usually follows a retardation in germination as a result of the inal)ility of the seeds to absorb water ra|)i(lly enough to bi'ing about the necessary physical and chemical transformations for the earlier stages of germination. (IS) Seeds that are to )>e sent to counti'ies having moist climates should he put up in air-tight packages. E\])eriments have shown that by the judicious us(> of l)ottles and paratlined ])ackages seeds can be preserved jiractically as well in one climate as in another. (ID) It is of th(^ utmost importance that tlu^ sei^ds be dry before })eing sealed in bottles or paraffined packages. A drying of ten days at a temperature of fi'om 30" to 35' C. (80' to 95 F.) will usually be sufficient. ITowev(>r, a l)etter method to follow is to dry until no more moisture is given off at a temperature equi\ alent to the maxi- mum of the region in which the seeds are to bo distributed. If this is not done, the subsecpient increase in temperature will li])erate an additional quantity of moisture, which ]>eing confined in the package will leave the seeds in a humid atmosphere and a rapid deterioration in vitality will follow. (20) Expei'iments in storing seeds in open and sealed ])ottles and in packages with definite (piantities of moisture and at various known temperatures have shown a very close relationship between the loss in vitality and the increase in water content, the deterioration likewise increasing with the t(Mnperature. {'■21) Of a series of experiments the average loss in vitality of seeds kept in envelopes in a "dry room" was 21.1!> i)er cent, "trade condi- tions" 30.03 per cent, " basement" -12.28 p(M- cent, whih^ the loss in the case of seeds stored in bottles was only 8.08, 3.92, and 4.51 per cent, respectively. (Sec Table XXV.) (22) Seeds under ordinary conditions of storage respire rpiite freely, and respiration is much more rapid if nuich moisture is present. Within certain limits respiration is directly proportional to the amount of moisture present in the seed and inversely proportional to the duration of vitality. (23) Respiration is not necessar}^ to the life of seeds, as they can he kept in conditions unfavorable for respiratory activity and still retain their vitality even better than under normal conditions of storage. Even though respiration be entirely prevented seeds will continue to deteriorate, and sooner or later lose their vitality. 90 THE VITALITY AND GERMINATION OF SEEDS. (24) The continued deterioration in tlio vitality of a seed after res- piration has ceased indicates a chemical activit}" within the cells, g-iving rise to a transfoi-niation of energy which sooner or later leads to the death of the seed. (25) Respiration is almost as active in the dark as in the light, pro- vided that the temperature and humidity remain the same. (26) Ferments and seeds lose all power of activity under similar conditions of moisture, and the former are undoubtedly of the utmost importance in metabolic activit}", but the evidence at hand goes to show that the life of a seed is not dependent on the preservation of the particular ferment involved or on the zymogenic substances giving rise to the enzyme. (27) The life of a seed is undoubtedly dependent on man}- factors, but the one important factor governing the longevit}^ of good seed is dry7i€ss. LITERATURE CITED. Bonnier, G., et Mangin, Louis. La fonction respiratoire cliez les veg6taux. Ann. sc. nat. bot., s6r. 7, 2: 365-380, 1885. Bornemann, G. Versuche iiber Erhaltung der Keimfjihigkeit bei importirten Ramen von Wasserpflanzen wiihrcnd des Transportes. Gai-tenflora, 35: 532-534, 1886. Also abstract in Bot. Jahresber., Jahrg. XIV, Abt. I, p. 132, 1886. Brown, Horace T., and Escomhe, F. Note on the intinence of very low tempera- tures on the gernnnative power of seeds. Proc. Roy. Soe. London, 62: 160-165, 1897-98. On the depletion of the endosperm of Ilordeum niJ(j(trc during germination. Proc. Roy. Soc. London, 63: 3-25, 1898. and Morris, M. Germination of some of tlie Grawinciv. Jour. Clit^m. Soc. London, 57: 458-528, 1890. Dammek, U. Verpackung und Versandt von Samen, welche ihre Keimkraft schnell verlieren. Zeitschr. f. trop. Landw., Bd. 1, No. 2, 1897. Abstract in Bot. Centralbl., 70: 190-197, 1897. De Candolle, Aug. Pyr. Physiologic v^getale (Conservation des graines), v. 2, p. 618, Paris, 1832. De Candolle, C. Sur la vie latente des graines. Arch, des sci. phys. et nat., ser. 4, 33: 497-512, 1895. Abstract in Amer. Gard., 18: 339, 1897. La vie latente des graines. Revue scientiilque, ser. 4, 4: 321-326, 1895. The latent vitality of seeds. Pop. Sci. Monthly, 51: 106-111, 1897. et PicTET, R. Recherches concernant Paction des basses tempt'ratures sur la faculty germinative des graines. Arch, des sci. phys. et nat., s6r. 3, 2: 629-632, 1879. Abstract in Just's Botan. Jahresber., Jahrg. VII, Abt. 1, p. 253, 1879. Action d'un grand froid prolong^ sur des graines. Arch, des sci. phys. et nat., ser. 3, 11: 325-327, 1884. Al)stract in Just's Bot. Jahresber., Jahrg. XII, Abt. 1, p. 26, 1884. Detmer, W. Vergleicliende Physiologic des Keimungsprocesses der Samen, Jena, 1880. Dew AR and McKendrick. On liquid air. Proc. Roy. Inst., 12: 699, 1892. Dixon, H. H. Vitality of seeds. Nature, 64: 256-257, 1901. LITERATURE CITED. 91 Dixox, II. II. On tlio germination of ^:('e(ls after exposure to iiii^li temperatures. Notes from the Botanical Scliool of Trinity Colle<>;e, Dublin, [i]!. 17()-18t), August, 190!i. Edwards et Colin. De 1' influence ratense. Bot. Zeit., 33 Jahrg. , ji. 52, 1875. Lleber die Einwirknng hoherer Temperaturen auf die Erhaltung der Keim- fiihigkeit der Samen. Cohn's Beitriige zur Biol, der Pflanzen, 2: 311-348, 1877. Kociis, W. Kami die Kontinnitiit der Lebensvorgilnge zeitweilig vollig unterbrochen werden? Biol. Centralbl., 10: ()73-686, 1890. Koi.KwiTZ, R. Uel)er die Athmung ruhenden Samen. Ber.d.deut.bot. Ges., 19: 285-287, 1901. Krasau, F. "Welche Wiirmegrade kann der Weizensame ertragen, ohne die Keim- fiihigkeit zu verlieren? Sitznngsber. d. Wiener Akad.d. Wiss., Abt. L, 48: 195- 208, 1873. Maquenne, L. Snr I'liygrometricite des graines. Compt. Rend., 129: 773-775, 1899. — Recherches sur la germination. Ann. agron., 26: 321-332, 1900. Contributions a I'etude de la vie ralentie chez les graines. Compt. Rend., 134: 1243-1246, 1902. Pic'TET, R. De I'emploi methodique des basses temperatures en biologie. Arch, sci phys. et nat., Geneve, 30: 293-314, 1893. PiETERS, A. J., and Brown, E. Kentucky Bluegrass seed — harvesting, curing, and cleaning. Bui. 19, Bureau of Plant Industry, U. S. Dept. of Agriculture, 1902. Romanes, C. J. Experiments in germination. Proc. Roy. Soc, 54: 335-337, 1893. Sachs, Julius. Beschiidigung und Ti'idtung durch zu hohe Temperatur. Handbuch d. exp. Phys. d. Pflanzen, Leipzig, 1865, p. 63. Sameic, J. Duration of the vitalitj' of some agricultural see germination of seeds. Thirteenth Annual Report, Mass. Hatch Agr. P^xp. Sta., pp. 74-83, 1901. 92 THE VITALITY AND GERMINATION OF SEEDS. Thiselton-Dyer, Wm. T. Influence of the temperature of liquid hydrogen on the germinative power of seeds. Proc. Roy. Soc, 65: 361-368, 1899. Thompson, A. Zum Verhalten alter Samen gegen Fermentlosungen. Ciartenflora, Jahrg. 45, p. 344, 1896. TowNSEND, C. O. The effect of ether upon the germination of seeds and spores. Bot. Gaz., 27: 458-466, 1899. Tkeviranus, Ludolph C. Physiologie der Gewilchse. Vol.11, p. 578, section 637, •1838. [Vitality of seeds as affected by age, heat, and moisture.] Uloth, W. Ue]>er die Keimung von Pflanzensamen in Eis. Flora, n. s., Jahrg. 33, pp. 266-268, 1875. Van Tieghem et Bonnier, G. Recherches sur la vie latente des graines. Bui. Soc. Bot. France, 29: 25-29, 149-153, 1882. Wartmann, E. L' influence de froids excessifs sur les graines. Arch, des sci. phys. etnat., Geneve, 8: 277-279, 1860. Recherches sur la v^g^tation (section 3— Role de froids excessifs). Arch, des sci. phys. etnat., Geneve, ser. 3, 5: 340-344, 1881. Waugh, Frank A. The enzymic ferments hi plant physiology. Science, n. s., 6: 950-952, 1897. Also Tenth Annual Report Vermont Agr. Exp. Sta., 1896-97. INDEX. rage. Agriculture, Department, Seed Laboratory, relation t( > present work 10 Alaliama, Auburn, seed-storinor ejxperiment 49 Alliinii rcjxt, Heleetion for exi)eriinent 10 Aniyliferous eells, relation to <,a'rnunation of seedjs, note 82 Angnria citndhis, Helection for experiment 10 Ann Arbor, Mich. , seed-storing experiment 50 testing experiment 14-22 Aplnccv, Daucns carota, selection for experiment 10 Apparatus for tests of effect of moisture on vitality of seed 30, 31 seed testing, description and use 11-12 AMeracesc, Lactuca satira, selection for experiment 10 Auburn, Ala., place for seed-testing experiments 14-22 Baton Rouge, La., comparison with Ann Arbor and Mobile for seed storing .. 21-22 seed-storing experiment 49 testing experiments 14-22 Bean seed, ice-house storage, effect 28 selection for experiment - - 10 Beans, germination tests, n-sults for various st()rage cimditions 51, 63-65 seed, respiration ex2)eriment, results 76 ' ' Valentine, ' ' tests 83 Bluegrass, Kentucky, Poti ]>riri(t ritrullus, selection for experiment - 10 Curing and drying of seeds, necessity for thoroughness 45 of seed, importance 87 De CandoUe, Aug. Pyr., remarks on conservation of seeds 44 suggestion regarding vitalitj' of seeds 75 C. , views on respiration of seeds 78 Diastase, iise in experiments on vitality of seeds 85 Dry atmosphere in open bottles, effect on vitality of seeds 34 sealetl 1 )ottles, effect on vitality of seed 34 heat, effect on vitality of seed, note 31 Drying and curing of seeds, necessity of thoroughness » 45 93 94 INDEX. Page. Dryness, most iiuportant factor in prolonged vitality of seed 90 relation to preservation of vitality of seed 87, 88, 89, 90 Endosperm of grasses, relation to germination, notes 82 Enzymes in seeds, part in preserving vitality 82-87 Escombe and Brown, experiments as to enzymes in germination 82 seed-germination experiment _ 80 views as to chemical action at liquid-air temperature. . . 79 Fabace.v, Pisum sativum and Phaseolus vulgaris, selection for experiment 10 Fazy-Pasteur, suggestion for storage of seed 45 Ferments, relation to vitality of seeds 90 unorganized, relation to vitality of seeds 82-87 Ferry Botanical Fellowship, seed study, relation to present work 10 Ferry, D. M. , & Co. , seed for experiments 10,15 Florida, Lake City, seed-storing experiment 49 testing experiment 14-22 Gardener, market, value of good seed 46-47 (jardeners, comjylaints of seeds, n(jte 13 "Geneva tester" for germination of seeds, modifications and use 11-12 Germination and vitality of seeds, conclusion from present study 87-90 of seeds at low temperatures 20-27 in ice house, effect of ])ackage 27, 28 various seeds, percentage under differing storage 63-(35 part of enzymes 82 tests and apparatus, discussion 1 1-13 results 50-65 Germinator, seed testing, method of use 12 Giglioli, c( )nclusion as to chemical activity in latent life 80 experiments with seed of Mediaujo sativa 79 remarks on vitality of seeds 45 Grasses, endosperm, relation to germination 82 Gray, contention as to suffocation of seeds 79 Qriiss, citation as to grass endosperm 82 Gulf of Mexico, effect of moisture on seeds 13 Hansteen, citation as to grass endosperm 82 Harvesting, relation to vitality of seeds 87 Heating, excessive, danger in curing seed 87 Hygroscope, crude, improvisation from awns in seed testing 31 Hydrolysis, presence in experiments on enzymes in seeds, notes 83, 84, 85, 86 Ice, packing of seeds, effect on vitality, remarks 26-29 Incubator, seed, test for effect of moisture on vitality 29 Indian Territory, Wagoner, i)lace for seed-testing experiments 14-22 seed-storing experiment 50 Jodin, seed-germi nation experiment, note ,. - 80 statement as to respiration of seeds 75 Keejiing seeds, discussion {see also Storage ) 65-74 Kochs, seed-respiration experiment 79 Laciuca sativa, selection for experiment - 10 Latent life, relation of chemical activity 80 Lettuce, comparison of storage in three climates -^~?? germination tests, results for various storage conditions 58, 63-65 seed, ice-house storage, effect 28 loss of vitality in tropical climate, note 25 moisture and temperature test of vitality 36 respiration exi)eriment, results 77 selection for experiment 10 Liliace.r, Allium cepa, selection for experiment 10 Longevity of seed, dryness most important factor 90 Lycopersicdn lucoperskum, selection for experiment 10 IMaquenne, statement as to seeds in low temperatures, note 81 suggestion as to res] iirati< )u of seeds 74 suggestions as to vitality of seeds 83 INDKX. 95 I'ago. Market i^anU'iicr, vulur of ixodd Hee*!, rciiiurks 4»>-47 INIatni-ity, relation to vitality n to vitality of seeds 89, 90 Romanes, seed resi)iration exiieriment - 79 Saniek, seed (jerniination experiment, note 80 Sharpe, citation as to enzymes 83 Shipping and keeping of seeds in special packages, discussion 65-74 storing seeds, method for preservation of vitality 44-65 seed in charcoal, moss, etc. , remarks 47 Soaking seeds for germination tests, advantage 12 ,Solannce:v, Lycopersicon bfcopenicum, selection for ex[)eriment 10 Spalding, Prof. V. M. , direction of present study 10 Starch in seed, relation to germination in ice-house storage. 28 Storage (keeping) and shipping of seeds in special packages, discussion 65-74 room, warehouse, character for seeds, remarks 46 seed, relation to jireservation of vitality 88, 89 Storing and shi])ping seeds, methods ior preservation of vitality 44-65 seeds, relative merits of Mobile, Baton Rouge, and Ann Arljor 21-22 Temperature and moisture, effect on vitality of seed, discussion 24-36 summary of results 35 relation to vitality of seed, tables and comment — 38-44 ]ireeipitation, relation to vitality of seed, percentages 23 maxinnnn limit of endurance by seed, variation 25 relation to vitality of seeds _ 87, 88, 89-90 Temperatures, tixed, effect of definite moist uie on vitality of seed, discussion.. 36-44 high, vitality of seeds, effect of moisture 29 Test, germination, first, for climate, results, tattle and connnent 15-J6, 18-21 second, for climate, results, table and comment 16-17, 18-21 Tester, Geneva, germination of seeds, modification and use 11-12 Testing seeds, conditions of experiments 14, 29-31, 36 Tests, germination, results 50-65 various vegetable seeds 11 seed, for effect of moisture on vitality at high temperatures 29 vitality, importance of nearness to planting time 47 Thompson, citation as to enzymes 83 Tomato, germination tests, results for various storage coiulitions (ii, 63-65 seed, ice-house storage, effect 28 moisture and temperature test of vitality 36 selection for experiment 10 Tropical climate, loss of vitality of lettuce seed 25 Vacuum, seed respiration experiments 79 Van Tieghem and Bonnier, tests of respiration of seeds, results 75 Violaceu', Viola tricolor, selection for exjieriment 10 Vitality and germination of seeds, conclusions from present study, sunuaury. . 87-90 caljbage and onion seed, relation to storage and jtackage 71-74 seed, effect of climatic conditions, discaission 13-22 definite moisture in fixed temperatures, discussion 36-44 temperature and moisture, discussion 24-36 enzymes in preservation j 82-87 loss for various seeds under different stcjrage conditions 63-65 in different climates, causes 22-24 with varying moisture at ordinary temperature 85 low, worse than dead seed, note 46 {)reservation by methods of storing and shipping 44-65 relation of moisture and temperature, tal)les and comment 38-44 storage in different kinds of jtackages, results 68 Warehouse, seed, storage, character, remarks 46 Water content of seeds, increase, effect on vitality 44 Watermelon, gemination tests, results for various storage conditions 62, 63-65 seed, ice-house storage, effect 28 selection for experiment 10 Waugh, citation as to enzymes 83 Zea mai/n, selection for experiment, note , 10 o _PMr'08