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Us... PARITMENE: OF AGRICULTURE:
BUREAU OF PLANT INDUSTRY—BULLETIN NO. 58,

B. T. GALLOWAY, Chief of Bureau.

THE

PVITALITY AND GERMINATION OF SEEDS.

J. We DEV EG,

ASSISTANT IN THE SEED IJARBORATORY.

BOTANICAL INVESTIGATIONS AND EXPERIMENTS.

WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1904.

we ee ERVIN EP OF AGRICULTURE.

BUREAU OF PLANT INDUSTRY—BULLETIN NO. 58.

B. T. GALLOWAY, Chief of Bureau.

f Ri ts Eat

VITALITY AND GERMINATION OF SEEDS.

BY
3 s
g Pu

Ky 9
J’ wr ty DUVEL,

ASSISTANT IN THE SEED LABORATORY.

BOTANICAL INVESTIGATIONS AND EXPERIMENTS.

Issuep May 28, 1904.

WASHINGTON:
GOVERNMENT PRINTING OFFICE.
Oras

BUREAU OF PLANT INDUSTRY.
Brverzty T. GAuutoway, Chief.

J. KE. Rocxkweur, Editor.

BOTANICAL INVESTIGATIONS, AND EXPERIMENTS.
SCIENTIFIC STAFF.
Freperick V. Covitin, Bolanist.

O. F. Cook, Botanist in Charge of Investigations in Tropical Agriculture.

Ropney H. True, Physiologist, Drug and Medicinal Plant Investigations.

Lysrer H. Dewey, Bolanist in Charge of Investigations of Fiber Plants.

EpvGar Brown, Botanist in Charge of Seed Laboratory.

Cart 8. Scorretp, Botanist in Charge of Grain Grade Investigations.

G. N. Couuins, Assistant Botanist, Tropical Agriculture.

A. ©. Crawrorp, Pharmacologist, Poisonous Plant Investigations.

Wituiam FE. Sarrorp, Assistant Curator, Tropical Agriculture.

F. H. Hitiman, Assistant Botanist, Seed Herbarium.

J. W. T. Duvet, Assistant, Seed Laboratory.

W. W. Tracy, Jr., Assistant, Variety Trials.

W. FF. Wiant, Assistant, Geographic Botany.

W. O. RicutMann, Pharmacognostical Expert.

Auicrk Henke, Assistant, Drug and Medicinal Plant Investigations.

W. W. SrocksperGcer, Expert, Drug and Medicinal Plant Investigations.
2

JAN 8 19
D. of b. 07

LETTER OF TRANSMITTAL.

U. 8S. DEPARTMENT OF AGRICULTURE,
BuREAU OF PLANT INDUSTRY,
OFFICE OF THE CHIEF,
Washington, D. C., March 26, 1904.

Str: I have the honor to transmit herewith and to recommend for
publication as Bulletin No. 58 of the series of this Bureau the accom-
panying technical paper entitled ‘* The Vitality and Germination of
Seeds.”

This paper was prepared by J. W. T. Duvel, Assistant in the Seed
Laboratory, and has been submitted by the Botanist with a view to
publication.

Respectfully, B. T. Gattoway,
Chief of Bureau.
Hon. JAMES WILson,
Secretary of Agriculture.

PREEAC E.

Because of variation in the amount and quality of each year’s crop
it is frequently necessary for seedsmen to carry over large quantities
of seeds from one year to another. Such seeds often lose their ability
to germinate, and either are a loss to the seedsman or, if they are
marketed, cause still more serious losses to those who plant them.
Since 1899 Mr. Duvel has been engaged in a general investigation of
the causes affecting the vitality of seeds, with special reference to the
conditions under which they are stored commercially. This investiga-
tion was begun in 1899 under the Dexter M. Ferry Botanical Fellow-
ship at the University of Michigan, and since September 1, 1902, it
has been continued by the United States Department 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 per-
centage of germination. It is now possible to speak with precision of
the extent of damage caused by careless methods of storage, to express
in actual figures the greater liability of seeds to loss of vitality under
the warm humid conditions existing in the South Atlantic and Gulf
States than under colder and drier conditions, and to demonstrate the
utility of storing seeds, when they must be kept in a humid climate, in
moisture-proof packages. A further investigation, i. e., of the extent
to which vitality may be preserved by means of commercial cold stor-
age, Is NOW In progress.

FREDERICK V. COVILLE,
Botanist.
Orrick OF BOTANICAL INVESTIGATIONS AND EXPERIMENTS,
Washington, D. C., December 5, 1903.

CONTE NES:

[DARN ONG i tee Ey ate er al ee
NicttenialcramcemlenhOds: 2 58.5. <.2 Aram aera ele ear oe Me bse ee eke
SISS0R Soha 225 eo eae Oe = nes ee ee
Germination tests and apparatus._...----------------------------------
Effect of climatic conditions on the vitality of seeds_.-........--.----:--...-
Causes of the losses in vitality in different climates ..... .-..--..--.--------
Effect of moisture and temperature upon vitality .-......-.. -.---.---------
SECON AG MOC sLSIG Cee Dat pS See Se Mee eee ee Se ge ok oe
Iffect of moisture on vitality at higher temperatures ._......------------
SADA OUN PERN ee agree a a ee a
Effect of definite quantities of moisture on the vitality of seeds when they are
kept within certain known limits of temperature _...........-..----------

A comparison of methods of storing and shipping seeds in order to protect
them from moisture, and consequently to insure a better preservation of

(PURSUING chee tte TR eg a eg
Suggestions of earlier investigators............---.-------------------+--
The necessity for thoroughly curing and drying seeds.......-.----------
Character of the seed warehouse or storage room ........-.-------------
The value of good seed to the market gardener .........----------------
Ship pinessceds i Charcoal, MOss, (ClC 5.2.22. 4.--ccacsseenges- onc. eee ee
Mature On, bic CXPehMeNts -2sechas -- a. cee cca ne eases eadbasaeesessees
PISPOsIMOUO! CG SaMNpleS=< si. . csc bos cece ee abic ss costae tee eee ee ses
Resultssoi.theveerminationutests. .25.o22.52c.cetc tek lteee cece ease e cose
Experiments in keeping and shipping seeds in special packages .....--------
RES IbAGlOMEOM SCEUS.- Sie 4 peer Toke RS ee oe en a See aie

SUDUOOUAGEEAY cre ies See iein, Se S52 2 SS Sa ne a a eee a eee
Enzymes in seeds and the part they play in the preservation of vitality ...--.
[SMUG ON OEE ip DE, ees en eo a een re ee
Interauure Cllcuneee Senne Sate a ee ee ee a Beno eh odes ded

PLLUS DR AS EG Ness

TEXT FIGURES.

Kia. 1. Apparatus used to determine the effect of moisture and temperature on —
the vitality of seeds in communication with free air.......-..:-----
2. Apparatus used to determine the effect of moisture and temperature ie

on the vitality of seeds not in communication with free air... ---- See

B. P. I.—94. B. I. E.—56.

THE VITALITY AND GERMINATION OF SEEDS.

INTRODUCTION.

It has long been known that the conditions under which plants are
erown and the degree of maturity at the time 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 be 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 temperature of the surrounding atmosphere,
the composition of the seed, the nature of the seed coats, activities
within the cells, and numerous other factors which play important
parts in the life of the seed.

The conditions necessary for the successful germination of a seed of
good vitality and the chemical transformations accompanying these
early 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 unexplained, and our knowledge will not be
complete until each and every species has been carefully studied.

On the other hand, the conditions influencing the vitality of seeds as
commercially handled are but little understood and have been almost
wholly neglected in research work. Likewise, but little attention has
been given to the complex chemical and physical changes which take
place in mature seed during 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 considerable practi-
cal value as well as of scientific importance. The present paper treats
chiefly of the conditions influencing the vitality and germination of
seeds when subjected to such methods of treatment 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
played by enzymes.

10 THE VITALITY AND GERMINATION OF SEEDS.

The results of the above experiments have suggested improved
methods of storing and shipping seeds so as to prolong their vitality
and also to secure the production of more vigorous seedlings.

The work for the present paper was begun in 1899 at the University
of Michigan and was continued for three consecutive years while the
writer held the Dexter M. Ferry Botanical Fellowship in that institu-
tion. During this time the investigation was under the direction of
Prof. V. M. Spalding, Ph.D., and Dr. F. C. Neweombe, who showed
great interest in it and gave valuable suggestions as the work pro-
eressed, at the same time placing the facilities of the laboratory and
of the library 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. 8.
Earle, Auburn, Ala.; Zimmer Brothers, Mobile, Ala.; Prof. H. H.
Hume, Lake City, Fla., and Prof. Charles B. Scott, San Juan, Porto
ICO.

MATERIALS AND METHODS.

SEEDS.

For these experiments thirteen different samples of seeds were used,
being so selected as to include representatives of ten different families
and twelve genera and species, as follows:

Poaceex—Lea mays, sweet corn (two samples).

Liliacee— Allium cepa i., onion.

Brassica oleracea i, cabbage; Raphanus sativus L.,

PBrasstcacesx
radish.

I pracee— Daucus carota Li... carrot.

Fuhacee— Pisum sativum Gee pea, Phaseolus vulgaris are bean.

Violacee— Viola tricolor Li., pansy.

Polemoniaceee— Phlox drummondadti Hook, phlox.

Solanacee— Lycopersicon lycopersicum (i.) Karst., tomato.
Cucurbitacee— Citrullus citrullus (.) Karst., watermelon.
Asteracee—Lactuca sativa l., lettuce.

It will thus be seen that the seeds used cover a wide range as to
family characteristics, as well as size, structure, and composition of
seed. Likewise they are all from plants of the garden or field that
have undergone a high degree of cultivation, thus enabling the seeds
to withstand more or less variation as to conditions of vitality and

growth.

All seeds used throughout these experiments were provided by
D. M. Ferry & Co., of Detroit, Mich., and the seed furnished was of
strong vitality and of known age and origin. The corn *‘ A” (Minne-
sota Sweet), onion (Yellow Danvers), pea (D. M. Ferry Extra Early),
bean (Yellow Kidney, Six Weeks), tomato (Dwarf Champion), and the

MATERIALS AND METHODS. 11

watermelon (Sweet Mountain) were grown in Michigan. ‘The corn
‘*B” (Minnesota Sweet), was grown in Nebraska, the cabbage (Win-
ningstedt), in Washington, and the lettuce (Black-Seeded Simpson), in
California, while the radish (Karly Searlet Turnip-Rooted), carrot
(Chantenay), pansy (mixed), and Phlox drummondii (mixed) were
grown in France. The seed was all of the harvest of 1899 and was
received at the botanical 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 80, 1900.
Percent- Percent-
rs ay ew. age of res a | age of
Kind of seed. germina- Kind of seed. germina-
tion, | . | tion.
BGS Tie ee ecco e ane eee ai ae ate! Sjale wrdlose 100 IPSS VWreepta tet en eget Bl A 69.5
OADDAS OMe tener eas Sone sti. | 93 1ofot eee Ae ee ae ae | 97
GOnYObwersmescete cas see ne clones ce ccee scl SBE | pOElsWhab:< SESS. Oh 3 Soo: Seon ee pe eee 78
(COMPAR WECUS EAS case emescocscecesesnen. Of |i Radish! oal2 222 een aes aan are Saas 81
Gonwrsweet cb. .cee sis. ocacsemeee ase: 88 | MOTTON ae EM ee Alans Sos Saas | 98
GUN teeters aian swine on icic onorsiaieints ayarala e's cre | 8725)1|| Watermelon. 2224 teceece. cece cts anes 99
OmiOnhese ese eseke s-4-ssccaeesacceeene | 98 |
|

GERMINATION TESTS AND APPARATUS.

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 described,
for it is simple and quite familiar to all. However, some modifications
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 originally and ordinarily used to support the folds of
cloth were replaced by glass rods of 6 to 7mm. diameter. Rods of
this size are much 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 suflicient space within the fold for the
seeds. On the other hand, in the germination of small seeds that
require considerable quantities of air, the folds can be closed at the
top by bringing the rods together, thus insuring more uniform condi-
tions throughout the fold and at the same time leaving suflicient space
above the seeds for an abundant supply of air. The chief advantage
in substituting glass rods for brass wires is in removing the possible
source of injury resulting from the poisonous action of the dissolved
copper.

Another error frequently, if not always, 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 way seeds are kept too moist, especially near the ends of
the folds. Likewise such methods give 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 obtained 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 much care was taken to see that there was only
avery small quantity 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 bottoms 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 fora
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 always be
of the best grade and should never be used a second time without being
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, but 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 comparatively well regulated and was maintained nearly
constant throughout most tests. Germinated seeds were removed daily
during early stages of the tests and a complete record of the number
germinating each day was kept. This is of value in seed testing,
because the germinative energy of a seed tells much as to its vitality.
If seeds have a high vitality, the germinative energy will be very
strong, 1. e., germination will take place rapidly, giving rise to strong
and vigorous seedlings; but if the seeds are of very low vitality, there
will be a corresponding retardation in germination, giving rise to
weak seedlings, 1. e., showing a low germinative energy. In most
cases throughout this work only the final 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, varies 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
humidity. 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 nonviable seeds sent out by seedsmen. Some grow-
ers have learned how to guard against this difficulty to a certain extent.
Zimmer Brothers, of Mobile, Ala., wrote, on February 28, 1900, con-
cerning this matter, as follows:

During thirty years’ experience in market gardening, we have learned that 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 package unopened until conditions are favorable
for planting. If we find it necessary to keep seeds of hardy plants for some months,
we put them up on arrival in dry bottles, put on top a bit of cotton saturated with
chloroform and cork tightly. We have kept, in that way, cauliflower seed. satisfac-
torily for twelve months. At the shore seeds keep very badly; one-half mile back
they do much better. As a rule seeds of tender plants give but little trouble.

As far as has been 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 vital energy. In
order to obtain reliable data on these points, a series of experiments
was undertaken in February, 1900, to determine how seeds are affected

14 THE VITALITY AND GERMINATION OF SEEDS.

when distributed to different parts of the United States and submitted
to the free influence of various climates. Likewise at the various
points where tests were made the seeds were subjected to different
treatments.

The places selected for these tests were San Juan, P. R., Lake City,
Fla., Mobile, Ala., Auburn, Ala., Baton Rouge, La., Wagoner, Ind. T.,
Durham, N. H., and Ann Arbor, Mich.

A sample of each species of seed was put up separately in double
manila coin envelopes and in closely corked bottles. Duplicate sets
of each series were then subjected at each of the above-named places
to the following conditions:

Trade conditions.—Conditions 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 subjected to natural varia-
tions in temperature and humidity. 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 comparatively constant.

Basements. —Rooms where the temperature was comparatively low
and uniform, and the relative humidity of the surrounding air was
much higher than in *‘ trade conditions” and ‘** dry 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 every kind of seed were
sent to the various testing places, where they were subjected to trade
conditions. At San Juan the packages of seeds were kept in an open
room, being subjected 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 comparatively 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

EFFECT OF CLIMATIC CONDITIONS. 15

college buildings. This door opens into a hall which communicates
with the oftices, chemical !nboratory, and the basement. At Ann
Arbor the seeds were stored in the botanical laboratory, with slightly
varying conditions, they being near a window which was frequently
open during the summer, and at irregular intervals during the early
part of the summer the packages were placed in the window so as to
receive the direct rays of the sun. The seeds stored at Ann Arbor
served partially as controls for those sent to the various other places,
and, in addition to the last-named series, seeds from the original
packages, as received from D. M. Ferry & Co., were kept in a dry
and comparatively cool closet on the fourth floor of the botanical lab-
oratory. These seeds served as checks for the complete set of exper-
iments, and are designated throughout this paper as ** Control.”

The samples were sent out to the above-named places in February,
1900. The first complete set was returned in June, or early July, of
that year. The second complete set was allowed to remain throughout
the entire summer, and was returned in October and early November
of the same year. The average time of treatment for the two series
of experiments was 128 and 251 days respectively. When 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 germination tests are given in Tables I and II. In
both tables the columns from left to right, beginning with Mobile,
Ala., are in the order of the degree to which the seeds were injured.

TABLE I.—Kffect of climate on vitality, as shown by percentage of germination—first test.

San Baton |Wagon-| Lake Dur- Au-

From Table [it will be seen that the loss of vitality 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 GERMINATION OF SEEDS.

phlox, where the germination was only 0.5 per cent, or a loss in vitality
of 99.3 per cent as compared with the control. These results were
closely followed by a loss in vitality of 95.9 and 92.7 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 percentage
of germination means seeds of a low germinative energy. Even
though the final percentage of germination be up to standard, the
retardation may be 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
47$ hours, while the seed returned from Mobile showed, during the
same time, a germination of only 12 per cent; yet the difference in the
final germination was only 0.3 per cent in favor of the control. Like-
wise the seed returned from San Juan germinated only 20 per cent in
474 hours, the final germination being 96 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 Table II. In the latter
case the seeds remained in the various places nearly twice as long as
those used for the first test.

Taste Il.—F feet of climate on vitality as shown by percentage of germination—second test.

Baton

— = = ers
Mobile.| Dur- Au- Lake | Wag- San
' Ala ©;! Rouge, | ham, | burn, | City, | oner, | Juan,
Feb I7| La., N-H., | Ala., Plas, india Paks Kear
=e nie Con- *~"| Feb.17 | Feb.17 | Feb.17| Feb.9 | Feb.17| Feb.9 | x.
Kind of seed. trol. | N to 6 to | to to to to to area
; one | Oct. 22. | Oct. 26. Nov. 19.) Oct.1. | Oct. 13.) June 20. ;
dave.) 2247 251 275 | 234 238 129
eae SCL ONS: days. | days. | days. | days. | days.
=< = - Slt | | ea | 7 | = }
Corn, sweet? HA ee cc ake jes 94.5 | 20.0 | 88.0 96.0 88.0 92.0 90:0 | (92:0 98.0
Corn, sweet, *°B*” ..2.2252- 88.5 12.0 | 54.2 82.0 62.0 | 77.0 78.0 78.0 80.0
OnIOM we. ees eee 97.0 | 0.0 0.5 0.0 1280) 4) 2655) 24.5 00.0 97.5
Cabbareaie. se cacnee eee 92.4 17.0 Deb e th A220, 61.5 63.5 70.5 W6o2 91.0
Radishieeecs soaeessce tee 78.8 51.0 | 55.5 59.5 63.0 58.5 60.5 62.0) “len 775
| |
Carroteeess 2 sacs sees 8240) |) 845 25.0 2:0 36.0 43.5 49.0 | 48.5 | 86.0
| | |
RGae Puce eset aee cones | 95.7 44.0 | 80.0 94.0 97.9 86.5 80.0 98.0 98.0
Beate. tai)8. 80. ccm 98.7 0.0 60.0 78.0 56.0 84.0 82.0 96.0 100, 0
PANS Vise see o eee 53.0 0.0 0.0 0.05] 4250 ila) Viet ey eka) 46.5
| = ~
Phlox drummondii ...-.--.- 53.9 0.0 0.0 OVS ea ateO 2.5 pty) |) alibi 10.0
MomatOzee= cc ncaes seer eeee 97.5 79.5 96.0 87.0 94,0 94.0 94.0 96.5 | 98.0
Watermelon. .</222.2e0--25 99 64.0 92.0 82.0 86.0 92.0 94.0 88.0 | 96.0
MetiMCh asta: see eee 92.3 20.0 84.5 88.5 86.0 85.0 82.0 | 83.5 92.5
Average of all seeds .| 86.77 | 24.31] 50.86] 52.42] 57.3 61.27 62.11 68. 21 84.58
|

EFFECT OF CLIMATIC CONDITIONS. 1%

Kven though the columns in both Tables I and IL are arranged in
the order of the loss in vitality as shown by the averages of the
various places, it will at once be seen that the relative degree of injury
did not remain the same throughout the experiment. This is probably
best explained by a variation in the climatic influences. It is evident
that in some of the places where seeds were stored the effects were
more deleterious during the time between the first and second tests
than they were during the first period of storage of 128 days. The
results given in Table II are of the greater value in showing the
relative merits of the different localities as places for storing seeds,
extending as they do over a longer period of time.

As a result of the second series of tests it was found that the average
percentage of germination of all of the samples of seed that were
stored in trade conditions at Mobile for 262 days was only 24.31 per cent.
This is equivalent to a loss in vitality of 71.98 per cent as compared
with the average percentage of germination of the control samples, the
average germination of the controls being 86.77 per cent. The pansy,
phlox, onion, and beans stored at Mobile wholly lost their power of
germination. The tomato seed, which proved to be the most resistant
to unfavorable conditions, gave a germination of 79.5 per cent, or a
loss in vitality of 18.46 per cent, as compared with the control sample,
which germinated 97.5 per cent. The degree of deterioration in the
seeds stored at the other places was much less marked than for those
stored at Mobile. The loss in vitality was only 41.39 per cent in the
seeds returned from Baton Rouge. The results from the seeds which
were stored at Durham, Auburn, Lake City, Wagoner, and San Juan
differed but little from those from Baton Rouge. The relative losses
in vitality are in the order given. The seeds kept in the packages
which were stored under trade conditions in the laboratory at the
University of Michigan showed a loss in vitality of only 2.52 per cent
as compared with the control, the seeds of which were stored ina cool,
dry closet on the fourth floor of the botanical laboratory. Ordinarily
a loss of 2.52 per cent would be considered as a normal variation due
to sampling and testing, and such was probably true in these two sets,
with the exception of the greater deterioration of the phlox, pansy,
and ** B” sweet corn, which were undoubtedly injured by the unfa-
vorable trade conditions, as repeated tests have shown.

From Table IL it will also be seen that the ‘‘A” sweet corn, peas,
tomato, and watermelon, with the exception of those returned from
Mobile, show a fair percentage of germination. In some cases the final
percentages of germination were even higher than the controls; but, as
previously stated, the final germination is not always a good criterion
for the determination of vitality, it being necessary to consider the
germinative energy as a basis for comparison. In order to show this
more fully some of the detailed results are herewith given in Table IIT.
These results show to a good advantage the degree to which germina-
tion has been retarded.

25037—No. 58—04——2

18 THE VITALITY AND GERMINATION OF SEEDS.

Tasie I1l.—Retardation in germination due to injury caused by unfavorable climatic
conditions.

Peas. Watermelon. Tomato.

Place where seeds
were kept.

Controle 222-6234; 81.3 94.5 79.6 95.7 98.0 99.0 78.0 92.7 97.5
Mobile, Ala ....... 4.0 20.0 a 24.0 44.0 0.0 64.0 1.5 1255 79.5
San Juan, P. R.... 64.0 92. 0 60. 0 98. 0 12.0 88.0 38.5 78.0 96.5
Baton Rouge, La .. 50.0 88.0 36.0 80.0 | 0.0 92.0 9.0 56.0 96.0
Wagoner, Ind. T .. 64.0 90. 0 36.0 80. 0 2.0 94.0 40.0 81.5 94.0
Lake City, Fla..... 68. 0 92.0 50.0 86. 0 | 0.0 92.0 | 16.5 65. 0 94.0
Durham, N. H..... 86.0 96.0 54. 0 94.0 | 0.0 82.0 0.5 5.5 87.0
Auburn, Ala....... 80. 0 88.0 a93.7 97.9 22.0 86.0 59.0 75. 94.0
Ann Arbor, Mich.. 82.0 98.0 82.0 98. 0 94.0 96. 0 75.5 91.0 98.5

a After 62 hours.

In order that the results of Tables I and II may be more readily and
fully comprehended, it has been deemed advisable to summarize them
in another table. For this purpose the average percentages of germi-
nation of all of the different 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 by 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 basis for comparison. ‘These
results furnish more trustworthy data as to the relative merits of the
different focalities as places for storing seeds. Likewise the per-
centages of deterioration between the time of the first 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 percentages of loss in the second series of
tests.

Average germina- | Deterioration in | Deterio-

tion of all seeds vitality as com- | ration in

used in experi- pared with con- | vitality

Place of storage. ments. | trols. between

iF ; | first and

First test.| © sds oe First test. Becond second

| Per cent. | Per cent. | Per cent. | Per cent. | Per cent.
Control): 225: eeeeesccosesreoeeee see sole sem ns oles see | 87.79 SG 7lu |e osss cece See eeeere ee 1.16
Mobile y Al asc ces ss 8a nome ee ncaa ce sects. eee 53. 59 24, 31 38.95 71.98 54. 64
San Juan, SPiiRisecs: eee eee seen ae eae oes eee ae ae fos 12! es | v.31! paca see
{| 45.18 |J || a 47.93 39. 86
Baton Rouse sia ste e see ees eee a ea 80. 48 50. 86 8.32 41.39 36.81
Durham SNH sees oo) sees eee Sea Seen 85. 57 52. 42 2.52 39. 58 38. 74
PANU ATT PAN Gy 2 Sat crce soya oe ree oe pee ternal ten rere 85. 70 57. 34 2.38 33. 91 33.10
Takes Citys c Bs ee eee ee ee ee ae ae 83. 00 61.27 5.45 29, 38 26.18
Wagoner, Inds Dy cs tens ra ee ee ean 82.12 62. 11 6.45 28.41 24.37
AnnvATbor, \Mich ses2=--neeeuet merece eee ace ee lee 86. 23 84.58 VE 2.52 OU

aCalculated results.

EFFECT OF CLIMATIC CONDITIONS. bys)

In Table IV the results are arranged in the order of the loss in vital-
ity as shown by the second tests. However, a few words of explana-
tion will be necessary, especially concerning the loss at San Juan. In
the first place, the seeds were kept at San Juan only 131 days” during
the early part of the summer, while during the most critical period,
June 20 to November 6, they were in the botanical laboratory of the
University of Michigan. Those marked Mobile, Ala., were, during
the entire time, 262 days, under the influence 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 approximately
the same. The average loss as shown by 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, with a loss of vital energy in the
seeds equal to 47.93 per cent. But more data are necessary before
such a gradation of injurious climatic influences can be established.

Table IV, however, brings out another interesting point, as shown
by comparing the results of the first and second tests at San Juan and
Mobile. In the first test the loss in vitality of the seeds from Mobile
was 38.95 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 Il. The degree to which the seeds
were injured while they were stored in San Juan was such that they
continued to deteriorate much more rapidly than the control sample.
This deterioration was most marked in the 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 always be 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 withstand greater changes in conditions
than seeds of low vitality without any marked deterioration. Through-
out these experiments a wide difference has been observed between
the ‘* A” sweet corn and the **B” sweet corn. The original tests
made January 30, 1900, at the time the seeds were received, showed a
germination of 94 per cent for the ‘‘A” sample and 88 per cent for
the ‘*B” sample of corn. The control tests, made in November, 1900,
showeda germination 0.5 per cent higher in each case; but the average
loss in vitality of the two samples of seed kept at the various places
was 12.17 per cent for the *‘ A” sample and 26.10 per cent for the ** B”
sample. As with the pansy and the phlox these samples showed that

«The number of days here given for San Juan is not absolutely correct. The time
was reckoned from the date the seeds were sent from the laboratory until they were
received in return.

20) THE VITALITY AND GERMINATION OF SEEDS.

the stronger the vitality of the original sample of seed the more harsh
treatment can be undergone without being injured. Strong vitality
implies long life as well as vigorous seedlings.

Another very important factor to be considered in the handling of
seeds is the relative resistance of seeds of various species to adverse
conditions. Certain seeds under one set of conditions may retain
their vitality exceedingly well, while seeds of other species of plants
under identical conditions may be killed ina comparatively short time.
For this reason no general rule can be laid down for the preservation
of seeds. Table V shows the varying degrees of deterioration of the
different species of seeds used in the experiments.

TasLe V.—Different degrees of deterioration of various kinds of seeds.

First test. Second test.
| Deterio- Deterio-
Average | ration in Average | ration in
Senay: ’ : rermi- | vitality 1 - | germi- | vitality
seed. Germi- sern | 3 srmi- Belt 3
Kind of seed rermi- | nation | ascom- |. C&™™!.| nation | as com-
nation of) -¢ - nation of
Gontrolt | eons the, pared " Outtol from the) pared
‘| various | with the} ~ * | various | with the
places. | control places. ) control

| Samples. samples.

MOMAtO- S222 Sa dedccasvice cece seater ease | 95.5 93. 06 2.55 97.5 92.43 5. 20
dig =| ep Ah me SR nm, i et Nt | 95.3 91.56 | 3. 92 | 95.7 84. 80 11.39
COLrn, SWEGU oral a Be atc acs seeecess | 95.9 94,75 | 1520 94.5 | 83. 00 APA Aly
Watermelomiss -c.2so ci. seeescs access | 98.3 | 97.75 Sy 99:0 86. 62 12.51
THOTEUCE Satie accisatepere wisieis Soler cures cewiae cied 81.6 80. 00 1.96 92.3 aed: 15.77
Ragishi ees ac 3S owswe kt Ao eee oe beset ae | 83.6 | 74.38 11. 02 78.8 60. 938 22.67
Corn paweet, SB. 2a. teen etew hee 89.3] 78.16 12. 47 88.5} 65.40 26.10
Boat + tee ne te nee | 98.7] 93.00 | 5.76 98.7] 69.50 29,58
Cabbare sees ie ee oe eee ee 92.7 86. 00 Woe 92.4 52.15 43.56
CaTrotetiseesse sen aa ware oo cere tee a nsee eee | 83.3 75.16 | 9.77 82.0 | 37.81 53. 89
OMIOM Ee pcee ose oes saeeeiane ee aneatiomes | 95.8 82.18 | 15. 26 97.0 | 25. 12 74.10
Parisy). ec ue Suectees eco se. Oe: |} 63.0] 38-87] 38:33) 158.0 8.00 84.90.
Phlox Grummondite: Poss 5.2 2ee. cack 69.0 14.87 | 34.97 | 53.9 7..62 85. 85

In the above table the list of seeds is arranged in the order of their
power to withstand the action of diverse climatic 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. Theaverage germination of the samples of tomato seed
kept at the various places was 92.48 per cent, or a loss in vitality 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 shown by the second
series of tests, is quite different from that of the first. This lack of
uniformity increases the difficulties 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

ditions, the order should have remained the same throughout, but the
wide variation in atmospheric changes affects different seeds so very
differently that no uniformity of results can be secured. For example,
the conditions prevailing from February until June were much 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 stages 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 off,
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 time that different
kinds of seed will retain their vitality. Put 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 obtain 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 cabbage, lettuce, and
onion seeds, put up in envelopes, as for the previous tests, were used.
The different packages of seed, placed in paper boxes from which
they were not removed, were sent from the laboratory on May 20,
1901, and were returned November 26, 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

T and II.

TasLe VI.—Relative merits of Mobile, Ala., Baton Rouge, La., and Ann Arbor, Mich.,

as places for storing seeds.

[Period, 190 days. ]

Cabbage. Lettuce. Onion.
NARA : Percentage of seeds | Percentage of seeds z . P
Ceeds ted t F High oreentare seeds ge >
s ceugen bec to germinated at the germinated at the Percentage of seeds ge rminated
ade condi- a 5 at the end of—
Moria end of— end of—
36 60 14 36 60 ib 60 | 84 108 |) 04
hours. | hours. |} days. | hours. | hours. | days. | hours. | hours. hours. | days.
= = — f 32% 2 eS” 4 E |e oe ee eS
: | |
Mobile, Ala......-- 0.0 0.0 S25 0.0] 14.0} 64.0 0.0 0.0 0.0 | 0.0
Baton Rouge, La .. 0.0 0.0 22°°5. 2.5 $5.5 74.0 0.0 0.0 0.0 | 0.0
Ann Arbor, Mich.. 10.0 64.5 86.5 67.0 82.5 96.5 3.0 10.0) 438.0 | 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 Mobile and Baton Rouge did not germinate,

a2 THE VITALITY AND GERMINATION OF SEEDS.

while seed from the same lot stored at Ann Arbor germinated 93 per
cent. The cabbage seed was injured nearly as much as the onion, the
sample from Mobile germinating only 8.5 per cent. The conditions
at Baton Rouge were slightly more favorable to the preservation of
vitality. The cabbage seed stored at the latter place germinated 22.5
per cent, while a like sample of seed stored at Ann Arbor germinated
86.5 per cent. The lettuce was much more resistant than either the
cabbage or the onion seed, but here, too, the injury was quite marked,
especially as shown by the retardation in germination. The conditions
at Mobile were also the most disastrous for the lettuce seed. During
the first 36 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 67 per cent. The
final percentages of germination were 64 and 96.5 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 Mobile. Here it will be seen, as in
Table V, that the onion seed was most sensitive and the lettuce seed
most resistant to the unfavorable conditions. In the first tests shown
in Table V the average loss in vitality of the lettuce, cabbage, and
onion was 15.77, 43.56, and 74.10 per cent, respectively, while for the
last tests, as shown in the foregoing table, the losses in vitality of
similar samples of seed kept at Mobile were 33.68, 91.29, and 100 per
cent, respectively. The ratio is practically the same in both cases, the
loss in the cabbage seed being 2.7 times greater than that of the lettuce.

The foregoing data are sufficient to indicate that climatic influences
play a very important part in the life of seeds, and that the degree of
injury varies greatly in different 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 San Juan, as shown
in Table I. After longer exposures, six or nine months, similar results
were obtained from all of the places to which seeds were sent. Many
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 vitality much sooner in some
localities than in others, the question naturally arises, ‘‘ Why this
loss in vitality?” 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, ina measure the loss in vitality is directly proportional
to the amount of rainfall. This deterioration is more apparent as the

CAUSES OF LOSSES IN VITALITY. 23

temperature increases, but the injury due to the increase in tempera-
ture is dependent on the amount of moisture present.

The following table has been compiled in order to show the ratio
between the loss in vitality and the precipitation and temperature.
The loss in vitality, as given in the second column of Table VII, rep-
resents the average losses in percentages, calculated from the results
of the germination tests of the 13 different samples of seeds, as shown
in Table II. ¢

The third column shows the annual precipitation in inches. The
annual precipitation has been taken, because in some instances heavy
rainfalls occurred just previous to the time that the seeds were put
into storage. Then, too, the annual precipitation furnishes more accu-
‘ate data for a basis of comparison. The mean temperatures, as given
in column 4, are 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
eritical period, in so far us temperature is concerned, is during the
summer months.

Taste VII.—Ratio between vitality, precipitation, and temperature. ?

Average

loss in vi- | Temperature
tality of Annual I ,
Place where seeds were stored, the 13 dif- | precipita-
| ferent sam- tion, —— =
| plesof | Mean Fahr, Maximum
seeds. an "~~ Rahr,
|
Per cent. | Inches. Degrees. | Degrees,
IMO DI Ghe Al Hie fae oa eee ace Qo Bo es Sends cioesis bos | 71.98 | 91.18 71.4 96.0
BarOUmRON Or ace cca se ane cemacesaskcec ces ok 86ce aie 41.39 66.37 A). 98.0
Pan amise NEVE 23s. eee Renae eee cite eee ea ae 39.58 18.20 5253 98.0
PAU PEIN TDR AU ihc aeeia ye, Sisk Someta ats clot maisiaciowic cals, vaia a ectstbes 33.91 | 62.61 64.4 98. 0
TAK CVOMLV EMH Mika svecie ae Sameer rae aes an cane oe mecad 29, 38 49. 76 W300 103.0
WSS ONTO TEOIUTL CAMP cfarcts Svars Saeiaearcimrsisis o Sistere xo sieieataten.cjaicialba 28. 41 42,40 | 67.1 167.0
PATAMEAT DOM WLC Sg oo es hose eroneels season atts « horses ce 2052 28.58 49,12 98.0
»aThese seeds were sent out in February, 1900, and were returned to the botanical laboratory and

tested in Oetober and November, 1900. The average time that the seeds were kept at the various
places was 252 days.

b The results of the San Juan tests have been omitted from this table beeause, as has been previously
stated, all of the seeds were returned from San Juan on June 20, 1900, when the first tests were made.
The seeond series of tests was made in October, 1900. During the time intervening between the first
and second tests the San Juan samples were kept in the botanical laboratory at the University of
Michigan.

According to the table the seeds kept at Mobile suffered the greatest loss in vitality. However, it is
quite probable that the greatest loss would have been from the seeds stored at San Juan had the time
of storage been the same for the two places, 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 Juan far exceeds those at Mobile. In 1900 there were 211 days on which rain fell in Gan
Juan, while the records for Mobile show only 146. Likewise the average temperature of the dew-point
for San Juan was 71° F. and only 59° F. for Mobile, which, when expressed in terms of absolute
moisture, gives 8.240 and 5.555 grains of water per cubie foot at the time of saturation. On the other
hand, the relative humidity of San Juan was 78.5 per cent, or slightly lower than that of Mobile, the
latter having a relative humidity of 80.5 per cent. However, the mean annual temperatures were
77.6° and 71.4° F., respectively, hence a mean absolute humidity of 7,099 grains of aqueous vapor for
San Juan and only 6.718 grains per cubie foot for Mobile,

24 THE VITALITY AND GERMINATION OF SEEDS.

From the foregoing table it will be seen that precipitation is a factor
of much greater importance than temperature. In order to show the
real value which the amount of precipitation furnishes as a basis 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 represented diagram-
matically as follows:

Effect of precipitation on vitality.

Place. Percentage of loss in vitality. Inches of precipitation.

Mobile? 22. 2S 3.22 2-6 71.98
Baton, Rouger sce. s2-2e 41.39
Durham. cases -- eae 39.58
AID UTT SE Rose see eee | 33. 91
Tuakker@ityeco ss cess. ce | 29.38 | 49. 76
Wagoner.........- eee 28. 41 | 42.40
Ann Arbor... 2222s2--5- Deb2 28.58

A discrepancy is very marked for Durham, N. H., 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 ina hall which opened directly into a chemical labora-
tory. It is quite probable that the low percentages of germination
were due to the injurious action of gases emanating from the labora-
tory. Of these gases, ammonia probably played a very important part,
as it is well known that seeds are very readily injured when subjected
to the action of ammonia.

It is to be understood that the above comparisons are somewhat
indefinite. If the amount of rainfall were equally distributed through-
out the year a definite ratio could, in all probability, be established;
but in the majority of places there are alternating wet and dry seasons,
which make such a comparison very difficult and unsatisfactory. Yet
for ordinary considerations it is sufficient to say that seeds will retain
their vitality much better 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 bringing about the premature death of
seeds and that the detrimental action of moisture is more marked as

EFFECT OF MOISTURE AND TEMPERATURE. 25

the temperature increases. Formerly the general consensus of opinion
has been to make this statement in the reverse order—that 1s, that
temperature exerts a very harmful action on seeds if much moisture
be present. For comparatively high temperatures the latter statement
at least it is not misleading, and in a certain

would probably 8
measure it is true; vat at the lowest known temperatures, as well as
at ordinary temperatures, moisture is the controlling factor, and in
order to be consistent it should likewise be so considered for higher
temperatures—that is, within reasonable limits.

That temperature is only of secondary importance is brought out in
the results obtained by a number of investigators. It has been well
established by Sachs,“ Haberlandt,’? Just,¢ Krasau,” Isidore-Pierre,¢
Jodin,’, Dixon,’ and others that most seeds, if dry, are 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 100° C. for one hour; but if the seeds contain comparatively
large quantities of moisture they are killed at much lower tempera-
tures. It has been reported that lettuce seed will 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 temperature has been raised to 114° 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 quite apparent. But if seeds are well
dried it can safely be said that they will not be 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 extremely
low temperatures is based on the experiments of Edwards and Colin,’
Wartmann,’ C. De Candolle and Pictet,? Dewar and MecKendrick,”
Pictet,’ C. De Candolle,” Brown and Escombe,” Selby,’ and Thiselton-

«Handbuch d. Exp. Phys. d. Pflanzen, Leipzig, 1865, p. 66.

»Pflanzenbau I, 1875, pp. 109-117; Abs. in Bot. sabeesb. 1875; ps 7717.

¢ Bot. Zeit., 33, Jahrg. 1875, p. 52; Cohn’s Beitrige zur Biol. der Pflanzen, 1877,
2: 311-348. .

“¢Sitzungsbr. d. Wiener Akad. d. Wiss., 1873, 4 : 195-208. I. Abth.

e Ann. Agron., 1876, 2: 177-181; Abs. in Bot. ine a 1876, Il. Abth., 4: 880.

/ Compt. Rend., 1899, 129: 893-894.

¢ Nature, 1901, 64: 256-257; notes from the Botanical School of Trinity College,
Dublin, August, 1902, pp. 176-186.

2 Ann. sei. nat. bot., ser. 2, 1834, 1: 257-270.

é Arch. d. sci. phys. et nat., Genéve, 1860, 8: 277-279; ibid., ser. 8, 1881, 5: 340-344.

JIbid., ser. 3, 1879, 2: 629-632; ibid., ser. 3, 1884, 11: 325-327.

k Proc. Roy. Inst., 1892, 12: 699.

! Arch. d. sci. phys. et nat., Geneve, ser. 4, 1893, 30: 293-314.

mYbid., ser. 4, 1895, 88: 497-512. .

” Proc. Roy. Soc., 1897-8, 62: 160-165.

6 Bul. Torr. Bot. Club., 1901, 28: 675-679.

26 THE VITALITY AND GERMINATION OF SEEDS.

Dyer.“ In the experiments of the last-named investigator seeds were
subjected to the temperature of liquid hydrogen (—250° to —252°C.)
for six hours, and when tested for vitality the germination was perfect
and complete. ? ;

Much more might be said on the effect of high and low temperatures
on vitality. But for the commercial handling of seeds the extremes
of temperature are of secondary importance and need not be further
discussed at this time. In the present work the purpose has been to
show the effect of moisture on the vitality of seeds when subjected to
such temperatures as are usually met with in the storing of seeds.

SEEDS PACKED IN ICE.

On February 6, 1900, samples of each of thirteen kinds of seed
were put up in duplicate, both in manila coin envelopes and in small
bottles. The bottles were closed with carefully selected cork stoppers.
These two sets of duplicate samples were then divided into two lots.
Each lot contained one of each of the packages and one of each of the
bottles of seeds. The samples thus prepared were carefully packed
with excelsior in wooden boxes, the boxes being then wrapped with
heavy manila paper. In one of the boxes was also placed a Sixes’
self-registering thermometer, so that the minimum temperature could
be ascertained.

These boxes were stored in a large ice house near Ann Arbor, being
securely packed in with the ice at the time the house was being filled.
The first box was taken out with the ice on June 12, 1900, after a lapse
of 126 days. The thermometer in this box registered a minimum of
—3.6° C. It is safe to assume that this temperature was uniform, at
least up to within a few days of the time when the seeds were taken
out. Unfortunately, absence from the university at this particular
time delayed an examination of the seeds until June 20. During the
eight intervening days the box of seeds was kept in the laboratory
and there many of the seeds in the packages molded, so that they were
unfit for germination tests. In fact, the results of the tests from the
packages are of little value within themselves; but in comparison with
the vitality tests of the seeds kept in the bottles some important facts
are brought out, and it has been deemed advisable to tabulate these
results with those of the second series.

The second box of seeds was packed approximately in the center of
a large ice house (100 by 60 by 20 feet) and was taken out with the
ice on July 21, 1900, after having been 167 days in cold storage. The

«Proc. Roy. Soc., 1899, 65: 361-368.
> Brassica alba (oily), Pisum sativum (nitrogenous), Cucurbita pepo (oily), Triticum
sativum (farinaceous), and Hordeum vulgare (farinaceous).

EFFECT OF MOISTURE AND TEMPERATURE. 27

box was brought directly to the laboratory and the seeds were exam.
ined at once. Those contained in the paper packages had absorbed a
considerable 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 used for the germination
tests care was taken to avoid using those that showed any trace of
a mycelium, thereby reducing the injury due to fungous growth toa
minimum, even though subsequent 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. Hight
of the peas, or 4 per cent, had already germinated, the radicles vary-
ing in length from 1 to 2.5 em., thus corroborating Uloth’s results in
germinating peas at or slightly below the temperature of melting ice.“

Taste VIII.—The vitality of seeds kept in an ice house in envelopes and bottles, and like-
wise the vitality of the controls.

First test, after 126 days. Second test, after 167 days.

Germination. Differ- | Differ- Germination. Differ- | Differ-
lence be- encebe- ence be-|ence be-

Kind of seed. tween | tween tween | tween

sam- | sam- sam- sam-

ples. ples. ples. ples.

Per ct. | Per ct. | Per ct. | Per ct. | Per ct.| Per ct.| Per ct.| Per ct.| Per ct. | Per ct.
MU OTT SAC anes fevare oe 96.0 36.0 94.0 60.0 58.0 92.0 86.0 96.0 6.0 10.0
Wom SB"? ss acc 5a... 90. 0 60.0 96. 0 30.0 36.0 92.0 74.0 94.0 18.0 20.0
OMLOMIAeS 22 oes ao 95.0 92.5 96.5 a5) 4.0 95.0 94.5 95.0 fm) 0.5
Cabbage’....<.=-...<. 93.5 89.0 94.0 4.5 5.0 92.0 90.0 94.0 2.0 4.0
RGISN es -keeccse. CASH 3h] ee Se eee Rees pare te 80.5 74.0 89.0 6.5 15.0
CATLODssc.c5< 5215.2 TIED Newser BOL) Pee sere | Ss acheter 73.5 52.0 75.5 21.5 23.5
ReMr tn. acscencicces 92730 ||s6 352-52 Bos UNM Sete osntece2 94.7 90. 0 96.0 4.7 6.0
SEC ae eon LOOK ae see bs T00u0) Ses = ee lea 100. 0 0.0} 98.0 | 100.0 98. 0
HANS) Ae .5 25: pees 52.5 5.0! 65.5 47.5 60.5 52.0 2.5 65.5 49.5 63.0
PWIOR a eisece ct cecs PaO) eyo @AGsD |i... 2-22 ava 54.0 11.0 68.5 43.0 57.5
MOMEBtOs= scaecas 22 9.5 | 73.0 93.5 22.5 | 20.5 96.5 51.5 96.0 | 45.0 44.5
Watermelon....... oS. 0 90. 0 100.0 $.0 | 10.0 100. 0 96. 0 100. 0 4.0 4.0
WG GUUILG Os ajatarssin acta SOKO Sees ac 66:0) 22-2 seal oo sto. 81.5 66.0 71.0) 15.5 5.0
Average ..... 87.3; 63.6) 87.9| 25.0| 27.7| 849] 621] 87.6] 243] 27.0

«In making up 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 moisture to destroy vitality, as is borne out by the second test.

The above table shows, as previously stated, that the results of the
first tests are incomplete and not very satisfactory, owing to the fact
that the germination tests were unavoidably delayed for eight days
after the seeds were taken from the ice house; but with the second set

@ Flora, 1875, pp. 266-268.

28 THE VITALITY AND GERMINATION OF SEEDS.

of sainples the counts for the vitality tests were begun within an hour
from the time the seeds were removed from the ice house. Thus, the
conclusions for these experiments must be drawn chiefly from the sec-
ond series of tests. However, comparisons will be made with the
first where such seem justifiable.

It will at once be seen that the seeds which were in paper packages
gave a much lower percentage of germination than either the control
samples or those kept in bottles. The average germination of the
controls was 84.9 per cent, and the average germination of the seeds
kept in bottles was 87.6 per cent, while only 62.1 per cent of the seeds
kept in paper packages germinated. This is equivalent to a loss in
vitality of 24.3 and 27 per cent, respectively, as compared with the
vitality of the control samples and the samples from the bottles. The
results of the first tests are practically the same, save that the differ-
ences between the control and the bottle samples are less marked. In
the second case the average vitality of the seeds kept in envelopes was
much reduced by 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 with onion, cabbage, and watermelon seeds. In
both the first and the second tests the germination varied but little
throughout. However, 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 kept in a moist atmosphere at normal temperatures, soon loses
its vitality, but when maintained at temperatures slightly below
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 quantities of starch, they
absorb more 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 been stored in bottles
in the ice house. The average germination of these samples was 2.7
per cent higher than that of the control. Ina measure this may be
included within the limits of variation; but when it is considered that
all of the bottle samples except the beans, tomato, and lettuce showed a
vitality equal to or greater than the control, it can hardly be considered
asa normal variation, especially since only the lettuce gave any marked
variation in favor of the control. Likewise, the average percentages

EFFECT OF MOISTURE AND TEMPERATURE. 29

of the first series of tests show a slight increase in favor of the seeds
kept in the bottles, though the increase is not so well marked and is
less uniform than in those of the second series.

Aside from the final germination there is still another factor that
must be taken into consideration as bearing evidence of the advantage
of 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 quite evident that the res-
piratory activities and accompanying chemical transformations were
much reduced by the reduction in temperature, and the vital energy was
thus conserved; but when the conditions were favorable for germination
the greater amount of reserve energy in these seeds gave rise to a more
vigorous activity within the cells and a corresponding acceleration in
germination.

Numerous other experiments showing the effect of moisture on the
vitality of seeds were made. In contrast to those just given, the
injurious action of moisture at higher temperatures, yet temperatures
well within the limits of those ordinarily met with in the handling of
seeds, will be next considered.

EFFECT OF MOISTURE ON VITALITY AT HIGHER TEMPERATURES.

This set of experiments was undertaken particularly to furnish con-
ditions somewhat similar te those existing in the States bordering on
the Gulf of Mexico, or, in fact, all places having a relatively high
degree of humidity and a temperature ranging from 30° to 387° C.
(86° to 98.6° F.) during the summer months. In order to secure the
desired degrees of temperature two incubators were utilized, one being
maintained at a temperature varying from 30° to 82° C., the other
from 36° to 387°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 incubators the seeds were subjected to four different
methods of treatment: 1. In a moist atmosphere, in free communica-
tion with the outside air. 2. In a moist atmosphere, but not in con-
tact with fresh air, the seeds being in. sealed bottles of 250 ce. capacity.
3. In a dry atmosphere, in free communication with the outside air.
4. Air-dried seeds in sealed bottles.

In order to obtain the conditions requisite for the first method of
treatment, an apparatus was used as shown in figure 1. The seeds were
put up in small packages and then placed in a 250 cc. bottle. The bottle
containing the packages of seeds was placed within a specimen jar
which was partially filled with water. This jar was then closed with
a large cork stopper which carried two glass tubes, each of 1 em. bore.
These tubes extended 25 cm. above the top of the jar and out through

30 THE VITALITY AND GERMINATION OF SEEDS.

the opening in the top of the incubator. The primary object of the
tubes was to prevent any water vapor from escaping within the incu-
bator and thereby doing damage to the seeds that were to be kept dry

Fic. 1.—Apparatus used to de-
termine the effect of moisture
and temperature on the vitality
of seeds in communication with
free air.

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
by afresh 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 ata tempera
ture varying from 36°
to 87" C. In both cases
the bottles contained
five packages of each of
the five samples of seed,
thus making provisions
for testing at different
intervals.

In order to supply 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 ina 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.

Fic. 2.—Apparatus used to
determine the effect of mois-
ture and temperature on the
vitality of seeds not in com-
munication with free air.

The bottles were then corked and sealed with paraffin, but were so

EFFECT OF MOISTURE AND TEMPERATURE. 31

constructed that the relative humidity of the inclosed air could be
increased without the admission of more free air. The detailed con-
struction of this apparatus is shown in fig. 2.”

The seeds continued to absorb moisture toa limited extent. In order
that the inclosed air might be maintained at approximately the same
degree of saturation, a crude hygroscope was attached on the inside of
each bottle. These hygroscopes were made from awns of Sé/pa
capillata L., the tip of the awns being removed and a short piece of fine
copper wire used as an indicator. These hygroscopes were suspended
from the under side of the cork, as shown at /, and by the side of each
was suspended a fine fiber of silk, which, being carried around by the
indicator, recorded the number of turns made by the awn.

Five such preparations were made for each of the two sets, so as to
furnish seeds for a series of tests. One set was kept at a temperature
of 380° to 32° C., the other at 36° to 87° C. The seed from one of the
bottles, at each of the temperatures, was weighed after eighty-one
days, at the time the germination tests were made. These weighings
showed that at the lower temperatures the average increase in weight
for all the seeds was 8.6 per cent, and at the higher temperatures, 6.3
per cent. The increase in the case of the beans was quite marked at
this time, being 13.3 per cent for those maintained at a temperature
ranging from 380° to 32° C., and 9.8 per cent for those maintained at
Beto ot G.

The third set of conditions consisted simply of packages of the air-
dried seeds kept in open boxes in each of the incubators. This series
of tests was made especially for the purpose of determining the effect
of dry heat on the vitality of seeds when maintained at the tempera-
tures above given for some considerable time.

For the fourth series small packages of the seeds were put into
2-ounce bottles, which were then corked and sealed with paraflin. Five
of these bottles were kept in each of the ovens and germination tests
were made at irregular intervals. The results of these tests furnish a

« The wide-mouth bottle (/) contains the packages of seed (s). Through an open-
ing in the cork is inserted a short piece of soft glass tubing, being first fused at the
lower end and having a slight constriction drawn atc. At a distance of 1 cm.
above the constriction is blown a small opening, as shown ato. <A short piece of
heavy rubber tubing (4), cemented ona piece of heavy brass wire (i), serves as a
stopper. This stopper, which must fit closely within the glass tube, is operated by
means of the heavy wire. When drawn up, the water in the tube may give off
aqueous vapor, which can escape through the small opening (0) into the bottle.
When suflicient moisture is present the supply is shut off by pushing the stopper
down firmly against the constriction. The stopper must be well coated with vas-
eline to prevent its sticking to the sides of the glass tube. To make the apparatus
more secure against the entrance of fresh air, a second piece of rubber tubing (7)
is placed in the upper part of the glass tube, the top of which is then filled with oil.

oe. THE VITALITY AND GERMINATION OF SEEDS.

basis for comparing the relative merits of keeping seeds in open vessels
and in sealed bottles.

Table LX will show the effect of the various methods of treatment
on the vitality of the seeds.

TasiE LX.— Vitality of seeds when subjected to the action of a dry and a moist atmosphere,
both when exposed to free air and when confined in glass bottles, at relatively high
temperatures, &

| | | Vitality of seeds when | Vitality of seeds when |
| kept ina moist at- | kept in a dry atmos-
| | mosphere. phere. Ger-
End of Hoviiie =a aaa ee i
Begin- | experi- a ‘In open bot-,| In sealed In open | Insealed | tion
= ie | ning of mentand ;~ | |tles, at tem- bottles, at | boxes, at | bottles, at of
Kind of seed. | experi- date of pee peratures tempera- tempera- | tempera- | con-
| ment. germina- eae varying | tures vary- | tures vary- | tures vary- | trol
|tion tests. ‘| from— ing from— | ing from— | ing from— | sam-
| | |_ = 2) ee = — | ples:
| '30° tol36° to'30° to!36° to/30° tol36° to/30° tol36° to
| BoE NES ios | e2oe oie occa sohoen | tozeculeoiee
| | |
| Days. P.ct.| P.ct.| P.ct.| P.ct.| P.ct.| P. ct.) P.ct.| P.ct.| P. ct.
Beans 2522255. 22%:< | Mar. 4) Apr. 4 31 |100.0 |100.0 | 78.0 | 44.0 | 86.0 | 84.0 | 98.0 | 98.0 | 94.0
DOT Grssnwaee = eee do....| May 12 69 | 97.5 0.0 , 75.0 0.0 100.0 | 90.0 | 92.5 | 95.0 | 98.7
Doe eee do....| May 24] 81] 94.0|...... 0.0 0.0 98.0 90.0, 98.0 100.0 | 98.0
DOrs acasesecens eee do July 22 140 Dee Miciete eve 0.0 0.0 |100.0 | 94.0 | 98.0 | 96.0 99,4
Cabbage ........-.|--- do....| Apr. 4] 31 | $7.8 | 90.5 | 73.0 | 72.5 | 86.5 | 84.0] 83.5 | 86.9] 91.0
|
DO Se ee aen ee eee do....| May 12 69 | 71.6 0.0 30.0 050))| 67.5) | 87.9 |) 7OSO UL 8sbe S8e0)
| | |
WO ees cece ler do....| May 24 BL 80HO ese ee 13.0 0.0 | 89.0 | 92.0 | 92.5 | 92.0 92.5
Do...te422 ce ap ee do....} July 22 TAO tO Os eee 05.0 1) 0:10) 48420: 83501 e8855 IKS6N7 | 93.1
| |
@arrotsss< 5 ee os 1_..do....| Apr. 4 31 | 83.5 | 77.5 | 54.5 | 29.5 | 84.5 | 88.0 | 89.5 | 89.0 | 92.5
r | [ | |
DOSS. 20 Ae 227d0-- 6.) May 12 69 | 69.5 | 0.0) 22:5 | 055. 82:0 |.8550")'88.5-1) 82.5: |" 4780
| |
DOie ieee ook 22d - 2. May 24] 81 | 48.0 ]....-. 2.5] 0.0] 44.5 | 50.0 | 50.0 | 48.0] 64.5
DO’ Sisco eae do....| July 22 140 OD DaR. eee Ob} 1Os0" P8120) | Si. 2. | 578457 |"83id 83.1
| | | |
L6G: sc. ee ces oe eee do =| Apr. { 31 | 92.5 | 90.5 | 78.0 | 58.0 | 91.0 | 86.5 | 91.5 | 90.0 | 90.0
190 eee a ete Peer do....| May 12 69 | 38.0] 0.0] 44.5) 2.0 | 42.0 | 38.5 | 38.5 | 51.5] 81.5
DOusrscee ees ...40....| May 24 S81) "bbs: [e222 se 1.0] 0.0 | 65.0} 58.5 | 62:.5.)°67.0))) 5325
Gta es2: Shee ..:do....| July 22} 140] 0.0 |...... 1.5] 0.0] 82.0 | 87.0 | 81.5 | 88.0 | 79.9
| | | |
(OhokVo ita See FaeGO! oscs) CAIs 31 | 95.5 | 89.0 | 64.5 | 45.0 | 95.5 | 93.0 | 96.0 | 97.5 | 96.0
DOU ...do....| May 12 69 | 68.0 | 0.0} 2.5] -0.0 | 97.0 | 95.0 | 97.5 | 93.0 | 98.5
DoysSeanesssses do....| May 24] 81 | 59.5 |....-- 0.0] 0.0 | 95.5 | 94.0 | 99.0] 95.0 | 96.5
MOg ae eee _..do = July 22: || 140.) 0/0'|..-.-- 0.0} 0.0 | 90.0 | 92.0 | 97.5 | 94.7 | 95.4
| |

aA study of the table will show that the lettuce and carrot seed germinated very poorly at the end
of 69 and 81 days. This, however, was not due to any inherent quality of the seed, but to an excess-
ive temperature at the time the tests were made. Both of these seeds require a comparatively low
temperature for their successful germination, lettuce germinating best at 20° C., and carrot at an
alternating temperature of from 20° to 380° C.

The amount of moisture absorbed or expelled under the different
methods of treatment has an important bearing on the duration of
vitality and will be considered briefly at this time. Only the general
results will be dise~ssed in this connection, inasmuch as later expert-
ments, carried out in a similar manner, show the detailed results to
much better advantage. Nevertheless, it requires only a glance at
the above table to show the marked difference in the germinative
power of seeds which have been stored in moist and in dry conditions.
The seeds which were exposed in a moist atmosphere to the higher

EFFECT OF MOISTURE AND TEMPERATURE. dd

temperatures (36° to 87° C.) were killed much earlier than those
subjected to the moist atmosphere at the lower temperatures—30~ to
32° C.—in both the open and the closed bottles.

A weighing at the end of 31 days showed that the average increase
in weight of the seeds kept in the open, moist chamber, due to the
absorption of moisture, was 6 per cent at a temperature of 380- to
32° C., and 5 per cent at a temperature of 36° to 37° C. For the
seeds kept in the oven, maintained at the temperature of 30° to 82> C.,
another weighing was made at the end of 134 days, at which time the
average increase in the water content had risen to 8.67 per cent.
Unfortunately the seeds from the second oven, maintained at the
higher temperature, had become badly molded in 69 days, so that only
the one weighing was made.

Vitality tests made at this time, 69 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 cabbage, lettuce, and onion.
Beans and carrot were most resistant, the former having germinated
2.3 per 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 (Karly Kidney Wax Six Weeks) having
become much darker and the lettuce (Black-Seeded Simpson) almost a
lemon color.

With the seeds constituting the second series, 1. e., 72 @ most atimos-
phere but in scaled bottles, the injury was much more severe. Here, as
with the open chambers, the seeds subjected to the higher temperatures
were killed first, even though the amount of moisture actually absorbed
was less, as was also true with the other series. A weighing made at
the end of 81 days gave an increase of 8.6 per cent for those from the
oven maintained at a temperature of 30° to 32° C., and 6.3 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
result 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 there is no reason to believe that these played any
part in the destruction of vitality. 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 been practically destroyed
at this time. The beans and onions failed to germinate, while the
O4

25037—No. 58 3

34 THE VITALITY AND GERMINATION OF SEEDS.

abbage, carrot, and lettuce germinated only 1, 2.5, and 1 per cent,
respectively.

During the succeeding 60 days much mold had 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 when 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
sume series kept at the higher 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, open and dry, presents quite
another factor. A weighing made at the end of 30 days showed that
there had been 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 nearly constant. Subsequent experiments, which
will be considered later, also show that the water capable of being
expelled at any given atmospheric temperature is driven off in a com-
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 many 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 temperatures at which the two ovens
were maintained, gave still another very different set of conditions.
Here there was 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 well 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 bottles, 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 been 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 84.82 per cent. At the higher temper-
atures—36° to 37° C.—the mean germination of the seeds from the open

EFFECT OF MOISTURE AND TEMPERATURE. =o0

and the closed bottles was 82.68 and 85.62 per cent, 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 following experiments.

Preparations similar to those above mentioned were used, and after
being subjected to a temperature of 87° C. for 219 days, there was no
appreciable loss in vitality, except the deterioration of 4 per cent in
the case of the cabbage seed that was kept in an open bottle, and 6.3
per cent in the seed from a closed bottle.“ But by increasing the tem-
perature, during an additional period of 68 days, from 87~ C. toa
maximum of 44° C., the injury was much more marked, especially in
the closed bottles. In the open bottles the vitality of the cabbage was
lowered from 91.3 per cent to 77 per cent, representing a loss in vital-
ity of 15.66 per cent. The onion seed fell from 95.7 per cent to 87
per cent when kept in an open bottle, and to 61 per cent when kept in
a closed bottle. The beans showed no apparent injury in either case,
except that they became very dry; consequently there was a retarda-
tion in germination as a result of the slow absorption of water.

The greater loss in vitality of the seeds kept in the bottles was the
direct result of the higher humidity of the air immediately surrounding
the seed, and not because there was a deficiency in the supply of fresh
air, as might be readily assumed. In the open receptacles the additional
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 gave
rise to a relatively moist atmosphere, and consequently 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 the sealed bottles had become 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 below 37° C, (98.6° F.), it being immaterial 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. (86° F.) works much 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 effect
of moisture is fully as great in open as in closed bottles.

“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 experiments just discussed furnish a fair criterion
by which to judge the vitality of seeds when influenced by tempera-
ture and moisture. It was still necessary to determine the effect of
definite quantities of moisture on the vitality of seeds when they are
submitted to temperatures well within the limits of that which may
be encountered in commercial transactions.

On December 19, 1900, preparations were made to determine these
factors. Seeds of cabbage, lettuce, onion, tomato, and peas were used
for these experiments, which continued for 70 or 72 days. All of this
seed was of the harvest of 1899 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 per cent; onion, 6.41
per cent; tomato, 4.71 per cent, and peas, 8.44 per cent.

The preparations were made as follows:

(a) Air-dried seeds were placed in bottles of 125 ce. capacity. The
bottles were closed with cotton plugs in order to protect the seeds
from dust while permitting a free circulation of air, This set served
largely as a check.

(>) Air-dried seeds were carefully weighed and then put into 125 ce.
bottles, closed with firm corks, and sealed with paraffin.

(¢, d, e, and 7) These samples were also carefully weighed and
sealed in bottles as 4, but in the different series of bottles there was
first introduced 0.5, 1, 2, and 3 cc. of water which had been previously
absorbed by small strips of filter paper.

(vy) The seeds constituting this series were first dried for 30 days at
a temperature of from 30° to 82° C. and then put up in bottles which
were sealed with paraftin. The loss in weight as a result of the dry-
ing was as follows: Cabbage, 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 above preparations was then subjected to different
degrees of temperature as follows:

(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, December 19, 1900, to February 28,
1901, varied from a minimum of —21.6° C. toa maximum of 8.9° C.

(2) In a fruit cellar having a comparatively low and uniform
temperature ranging from 10° to 13° C,

EFFECT OF DEFINITE QUANTITIFS OF MOISTURE. oe

(3) In the ‘dark room” of the botanical laboratory, which was
quite dry and maintained at a temperature of 20° to 22° C.

(4) In the herbarium room on the fourth floor of the botanical labo-
ratory. The air here was very dry and the mean temperature about
the same as for No. 38, but with a much wider variation, reaching at
times a maximum of 30° and a minumum of 10° C.

(5) In an incubator maintained at 30° to 32° C,

(6) In an incubator maintained at 37° to 40° C.

It will be observed that all of the 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 70 or 7
days by again carefully weighing the seed, after which germination
tests were made. The results of the germination tests and the gain or
loss in weight are given in Table X.

)
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SEEDS.

THE VITALITY AND GERMINATION

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{ 4

40 THE VITALITY AND GERMINATION OF SEEDS.

The foregoing table, showing the conditions under which the seeds
were kept, has been made quite complete. Aside from the final per-
centages of germination, the percentages of germination after a defi-
nite number of hours have likewise been given, the latter being better
expressed as germinative energy. The germinative energy, as has been
previously stated, is an important factor in determining the potential
energy of a seed. This is quite clearly shown in many of the germi-
nation tests recorded in the above table. The preliminary results show
a marked contrast as a result of the different kinds of treatment, while
the final results reveal nothing more than the regular degree of varia-
tion usually met with in testing seeds. Of the five species of seeds, the
onion has yielded the most striking variations in the earlier stages of
germination. Take, for example, No. 1535, the sample that was kept
in an open bottle in the fruit cellar. The moisture absorbed was sufli-
cient to cause a chemical transformation, which injured the vitality of
the seed and consequently caused a retardation in germination. No.
1539, the onion seed from the incubator maintained at a temperature
of 87° to 40° C., germinated only 16.5 per cent in 77 hours, while
the final percentage of germination was 95.5 per cent. Onion seeds
Nos. 1532 and 1533 germinated in 77 hours 18.5 and 2.5 per cent
respectively, while the final germination of the former was 98.5 per
cent and of the latter 96 per cent. All of these tests gave final per-
centages of germination somewhat higher than the mean of the control
samples. But the germination was considerably retarded, the control
samples haying germinated 29.5 per cent during the first 77 hours.
These retardations in germination must be due to a lowering of vitality,
asa more careful study of the table will show, and not to any excessive
drying that may have taken place during 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 they all be pointed out and discussed here.

The table also shows the results of the various 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 increase
was quite marked in all cases where free water was introduced. The air-
dried seeds that were sealed in bottles without the introduction of free
water all increased slightly in weight, with the exception of the peas,
which showed a slight decrease in weight. It has been observed that
the absolute loss in the weight of the peas was slightly greater than
the total gain in the four other samples of seed. This, however, is
not of sufficient uniformity throughout to fully justify the conclusion
that cabbage, lettuce, onion, and tomato seed have a greater affinity for
water than peas, and that the former robbed the latter of a portion of
their water content. Yet a portion of the increased weight of the
cabbage, lettuce, onion, and tomato seed is probably best accounted

EFFECT OF DEFINITE QUANTITIES OF MOISTURE. 4]

for in that way. On the other hand, it is quite probable that a por-
tion of the increase in weight was due to the results of intramolecular
transformations and to the coexistent respiratory activities of the
seed. The means of making these determinations are far from easy.
Van Tieghem and G. Bonnier have shown“ that seeds kept in sealed
tubes in atmospheric air increased in weight during two years, but the
increase was very small. In their experiments the peas which were
in sealed tubes increased 74,5 of their original weight. A corresponding
sample kept in the open air increased ;!; of its original weight.

Nos. 1540 to 1545 in Table X show an increased weight in seeds
when sealed in bottles for 70 days. These seeds were previously
dried for 30 days at a temperature of 30° to 32°C. Disregarding the
increase in weights as above given and the factors to which such
increase may be attributed, it is quite evident that in all cases where
water was added the increase in weight was due chiefly to the absorp-
tion of the water. The absolute increase was approximately the same
as the weight of the water added.

The amount of water absorbed by different seeds varies greatly
under identical conditions, depending largely upon the nature of the
seed coats and the composition of the seed. The average increase in
weight of the seeds used in these experiments was as follows: Onion,
6.27 per cent; pea, 5.51 per cent; cabbage, 4.12 per cent; lettuce, 3.99
per cent; tomato, 3.99 per cent. The loss in vitality of the corre-
sponding samples was 28, 12, 23.7, 18.5, and 14.7 per cent, respec-
tively. The relationship here is quite close, the amount of water
absorbed being roughly proportional to the loss in vitality. The
peas, however, afford an exception to this general statement. But it
must be remembered that peas require a much larger percentage of
moisture to start germination and are likewise capable of undergoing
much wider variations than the other seeds in question. However,
before a definite ratio can be established between the absorption of
water and the loss in vitality, many other factors must be taken into
consideration, such as the composition, water content, and duration of
vitality of the seed under natural conditions.

Another interesting factor is shown in No. 1546 of Table X. These
seeds were dried for 30 days at a temperature of 80° to 82° C., after
which they were kept in an open bottle in the laboratory for 40 days.
During the 30 days’ drying the cabbage lost 2.41 percent, lettuce 2.59
per cent, tomato 2.71 per cent, and the onion 3.47 per cent of moisture.
These same seeds when exposed to the free air of the laboratory for 40
days never regained their original weight, the increase being as follows:
Cabbage, 0.6 per cent; lettuce, 0.58 per cent; tomato, 1.56 per cent;
onion, 0.89 per cent. The average quantity of water expelled was 2.79

a4 Bul. Soc. bot. France, 29: 25-29, 149-153, 1882.

49 THE VITALITY AND GERMINATION OF SEEDS.

per cent in 80 days, while the average increase in weight during the 40
days was only 0.91 per cent. These results show that if seeds are once
carefully and thoroughly dried, they will remain so; that is, if kept in
a comparatively dry room. This is an important factor in the preser-
vation of vitality, as is borne 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 effect of the dry-
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 by the seeds, with a
limited amount present in the bottles, was inversely proportional to the
temperature. At the higher temperatures the inclosed air held a larger
portion as water vapor; however, there was a greater deterioration in
vitality. Where the seeds were kept outdoors at the low temperatures
(—21.6° to 8.9° C.) of the winter months, no injury was apparent
except where 3 ce. of water was added, and then only the onion seed
was affected. This sample of seed had absorbed a quantity of water
equal to 10.38 per cent of the original weight, which together with
the original water content (6.41 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 18° 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 temperature; but even here the
seeds in the bottles which contained 0.5 ce. of free water deteriorated
very little. The injury was confined to the onion seed, which showed
a slight retardation in germination. Where 1 cc., 2 ce., and 3 cc. of
water were added, vitality in some instances was likewise remarkably
well preserved. 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 the tomato seeds
suffered only sufficiently to cause a delay in the rapidity with which
they germinated. The cabbage seed was retarded with 2 ec. and a
lowering of the final percentage of germination with 3 cc. of water.
The onion seed, being very sensitive to these unfavorable conditions,
deteriorated very greatly, being practically worthless where 3 cc. of
water were added. <A brief study of the table will readily show that
many seeds were killed at the still higher temperatures of 80° to 82°
C. and 37° to 40° CG. The onion seed was slightly injured even where

EFFECT OF DEFINITE QUANTITIES OF MOISTURE. 43

no water was added. However, a temperature of 40° C. is sufticient
to injure many seeds, even though the liberated water be permitted to
escape, as is shown in the tests of the onion, No. 1539 of the table.
The greatest injury when air-dried seeds are sealed in bottles and then
subjected to a higher temperature is due to the increased humidity of
the confined air, asa result of the water liberated from the seeds.

At first glance some of the conditions given in the above table 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 with the seeds kept in the bottles with 3 ce. of
water where the additional amount of moisture absorbed eave rise, in
some of the seeds, to a water content of approximately 20 per cent.
Yet this need not be thought of as an exception, for such extreme
cases are often encountered in the commercial handling of seeds.
During the process of curing even more drastic treatment is not
infrequently met with. Pieters and Brown” have shown that the
common methods employed in the harvesting and curing of Pow pra-
tensis Li. were such that the interior of the ricks reached a tempera-
ture of 180° to 140° F. (54.4° to 60° C.) in less than sixteen hours, at
which temperature the vitality of the seed is greatly damaged and
frequently entirely destroyed. The interior of one rick reached a
temperature of 148° F. (64.4° C.) in twenty hours, and the vitality
had decreased from 91 per cent to 3 per cent, as shown by the ger-
mination of samples taken simultaneously from the top and from the
inside of the same rick.

On the other hand, the extreme cases need not be considered.
Take, for example, the onion seed that was sealed in a bottle with
1 ce. of water and maintained at a temperature of 387° to 40°C. The
increase in weight due to the water absorbed was 3.91 per cent, thus
giving a moisture content of 11.2 per cent and a complete destruction
of vitality. The cabbage seed, kept in the same bottle, had absorbed
a quantity of water equivalent to 2.35 per cent of its original weight,
which, with the 5.90 per cent contained in the original sample, gave
8.25 per cent of water. This sample of seed germinated only 11 per
cent, having thus no economic value. In neither of these samples
was the amount of water present in the seeds greater than that ordi-
narily found in commercial samples. Moreover, the temperature was
much below that frequently met with in places where seeds are
offered for sale and likewise well within the limits of the maximum
temperature of our summer months, especially in the Southern
States. Take, by way of comparison, the maximum temperatures of
some of the places at which seeds were stored to determine the effect
of climate on vitality, as shown in another part of this paper. During

4 Bulletin 19, Bureau of Plant Industry, U.S. Department of Agriculture, 1902.

EE VW LaPAT Tay:

AND GERMINATION

SEEDS.

the summer of 1900 the maximum temperature at Wagoner, Ind. T.,
yas 107° F. (41.1° C.), while that of Lake City, Fla., was 103° F.

(3925°.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:

Taste XI.—Marked deterioration

content of seeds.

in vitality with an increase in the quantity of the water

| Average in-| Average
Amount of water | _ CTease 1n moisture In | Average
7 wane ey Terri : | weight asa | seeds at the cane
How preparations were made. introduced into Ries tl 3 Sahar germina-
the bottles resulvortthe | tine Sern, tion
| os greater water) nation tests ;
content. were made.
| CG: Per cent. Per cent: Per cent.
Controlisam ple). 2. 2 - oe mitin sb wie Se eens ce SE ekintee wielaiai tents ein atereralll eee oaeiesies 6.07 | 93.3
Closed bottles, sealed with paraffin.....-. Water expelled. 0. 06 Bei | a 93.9
1 DF 0 Se Seen peee Se ee seers bey is sh oneten tn Panee Car a ee None. .08 6.55 94.0
DO rye iiss tea bs ote oooe seecbecc eee 0.5 1275 8.3 91.7
PO nce os eee eee Seno See eee 10 3. 24 9.91 83.3
| DY 8 lpr nnn ey ER MEN Dee ae Se Be 2.0 5.91 12575 67.5
POG pcan mea eae coe ee ae aeee See 3. 0 8.13 15:10 58.6

a Peas not ineluded in this set.

Numerous other results of a similar character might be cited, but it
hardly seems necessary at this time, since there can be no doubt that
moisture is the prime factor in causing the premature destruction of
vitality in seeds in the usual conditions of storage. Why they lose
their vitality as a result of the unfavorable conditions is quite a differ-
ent question, and has to do with the very complex composition 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.

SUGGESTIONS OF EARLIER INVESTIGATORS.

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 necessary 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 be preserved for a much longer period.

«Physiologie Végétale, Paris, 1882, Tome II, p. 618,

COMPARISON OF METHODS OF STORING AND SHIPPING. 45

Giglioli” goes so far as to say:

There is no reason for denying the possibility of the retention of vitality in seeds
preserved during many centuries, such as the Mummy wheat and seeds from Pompeii
and Herculaneum, provided that these seeds have been preserved from the begin-

ning in conditions unfavorable to chemical change. * * * The original dryness

of the seeds and their preservation from moisture or moist air must be the very
first conditions for a latent secular vitality.

Some of the earliest suggestions for storing seeds in quantity were
made by Clément and Fazy-Pasteur, and were reported by Aug. Pyr.
De Candolle in his Physiologie Végétale. Clément suggested the use
of large cast-iron receptacles, made impervious to air and water, the
well-dried seeds to be poured in through an opening at the top, after
which the opening should be hermetically sealed and the seeds with-
drawn through an iron pipe and stopcock at the bottom of the tank.
The scheme of Fazy-Pasteur was to store seeds in wooden boxes well
covered with tar. This method was especially applicable to small
quantities 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 by Clément, has

never been practiced to any extent. It seems quite possible, however,
that the present ** tank” grain elevator, now so universally used, might

readily be modified in such a way as to make the method suggested by
Clément quite practicable.

THE NECESSITY FOR THOROUGHLY CURING AND DRYING SEEDS.

In addition to being well matured and carefully harvested, seeds
should be thoroughly cured and dried before being put into the stor-
age bins. Much better results would be obtained 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 consequently the seeds are
better prepared for storing and shipping. Experiments made with

abbage, lettuce, onion, and tomato seeds gave results as follows: The
average loss in ee of the air-dried oe after an additional dry-
ing of 30 days at a temperature of 30° to 32° C. was 2.79 per cent.
Yet these same seeds, when kept for 40 days in the laboratory, reab-
sorbed only an average of 0.91 per cent of moisture. Like quantities
from the original sample gave only the slight variations ordinarily met
with, due to the humidity of the atmosphere. Thus seeds, when once
varefully and thoroughly dried, will not regain their original weight,
provided they be kept in a dry room.

@ Nature, 1895, 52; 544-545,

46 THE VITALITY AND GERMINATION OF SEEDS.
CHARACTER OF THE SEED WAREHOUSE OR STORAGE ROOM.

Another important factor in the storing of seeds is the character of
the seed warehouse or storage room. ‘The first point to be considered
is dryness. Such houses should be kept as dry as possible, which can
be accomplished either by means of artificial heat or by the use of
strong drying 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 be 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 must
determine for himself whether or not this loss is sufliciently 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
artificially heated. The averages of the thirteen samples of seeds from
the eight places at which they were stored show a difference in the
loss of vitality of 9.87 per cent. Those kept in rooms that were arti-
ficially heated during a greater portion of the time deteriorated 25.91
per 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 Rouge, La. At Lake City, Fla., the
relative percentages of deterioration were 29.42 and 16.27 for the
unheated and heated rooms, respectively; at Auburn, Ala., 33.90 and
10.34 per cent, and at Durham, N. H., 39.58 and 3.57 per cent, respec-
tively. Unfortunately 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 GOOD 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
where 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 delay,
making the difference between success and failure in the desired crop.
Seed of low vitality is even worse than dead seed. With the latter the
difficulty is soon discovered, while with the former, although the seed
will germinate, the seedlings are not sufficiently vigorous to develop

COMPARISON OF METHODS OF STORING AND SHIPPING. AZ

into strong and healthy plants. True, most enterprising gardeners
usually have vitality tests made immediately preparatory to planting,
but this is not always convenient, and they rely on the results of tests
made at some earlier date. In such cases it quite frequently happens
that they accept the results of tests made several weeks earlier. With
many seeds this will suffice, yet there are many others that will dete-
riorate very materially within a few weeks or even within afew days
in such unfavorable climates as exist, for example, near the Gulf of
Mexico. Ina letter dated January 15, 1903, Mr. J. Steckler, of New
Orleans, La., wrote as follows concerning the vitality of seeds:

Some seeds are not worth being planted after being here three months. This is
especially true of cauliflower seed. We have-made repeated tests and this seed after
remaining here 90 days was worthless and had to be thrown away.

SHIPPING SEEDS IN CHARCOAL, MOSS, ETC.

Bornemann” made some experiments with seeds of V/etor/a regia
and Huryale forox, in which he found that when packed in powdered
charcoal they soon lost their vitality, but when packed in powdered
chalk slightly better results were obtained. On the other hand,
Dammer? recommends powdered charcoal as a method of packing for
seeds that lose their vitality during shipment, especially the seeds of
palms and a number of the conifers.

Charcoal is undoubtedly much better than moist earth or moss,
which are frequently used, the latter affording abundant opportunities
for the development of molds and bacteria during transit. Some such
method as moist charcoal is necessary in case of seeds which lose their
vitality on becoming dry. Numerous other reports have been published
from time to time concerning the shipping of seeds of aquatic plants,
us Wellas those of low vitality, but they need not be discussed further
at this time.

NATURE OF THE EXPERIMENTS.

Aside from some popular accounts and miscellaneous suggestions,
but little has been done toward finding improved methods of shipping
and storing seeds of our common plants of the garden and field.
Accordingly, in February, 1900, a series of experiments was under-
taken to determine some of these factors, in which 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 immediate external conditions are best suited for the
longevity of seeds? (3) What part do climatic conditions play in
affecting the life of seeds?

«Gartenflora, 35. Jahrg., 1886, pp. 532-534.
> Ztschr. trop. Landw., Bd. I, 1897, No. 2.

48 THE VITALITY AND GERMINATION OF SEEDS.

In order to answer the first question, duplicate samples of the various
kinds of seeds were put up in double manila coin envelopes, as
described on page 14. Likewise, duplicate samples were put up in
small bottles, the bottles being closed with good cork stoppers. Some
of the bottles were filled with seed, while others were only partly full.
In some cases there was a surplus air space five times as great as the
volume of the inclosed seeds. This space, however, had no b ring
on the vitality of the seeds as far as could be determined.

In order to determine what immediate external conditions play an
important part in the destruction of vitality, samples of seed, prepared
as above described, were stored in different places. At each place
they were subjected to three different conditions of storage, which, for
convenience, have been designated as ‘* trade conditions,” ‘*dry room,”
and ** basement,” as described on page 14. In addition to these three
methods of storage, numerous other conditions were tried in and near
the laboratory; 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, ete.

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 vitality, page 18. 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 comparing the vitality of
seeds when stored in paper packages and in bottles, 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:

San Suan, P. P.—The seeds were sent to San Juan on February 9,
1900, and were returned on June 20, 1900, after a lapse of 131 days.¢
At San Juan the seeds were stored under trade conditions only, and
the various packages were not removed from the original box in which
they were sent. While in San Juan the box 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, P. R.; Lake City, Fla.; Mobile, Ala.; Auburn, Ala.; Baton Rouge, La.;
Wagoner, Ind. T.; Durham, N. H., and Ann Arbor, Mich.

» The places of storage represented by trade conditions have already been described
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 basement 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.

COMPARISON OF METHODS OF STORING AND SHIPPING. 49

Lake City, I’la.—The seeds were sent to Lake City on February 9,
1900. The first complete set was returned on June 18, after 129 days.
The second complete set was returned October 1, after 234 days. The
‘*trade conditions” at Lake City were supplied by keeping the seeds
in a small, one-story frame building, the doors of which were open the
greater 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 floor of the
main building of the Florida Agricultural College. The third set was
kept in a small bulletin room in the basement of the same building.

Mobile, Ala.—The seeds were sent to Mobile on February 17, 1900.
One set was received in return on July 7, after 180 days. The other
set was received on November 6, after 262 days. The ‘* trade condi-
tions” in this case consisted of a comparatively open attic in a one-story
frame dwelling. The set ina ‘dry room” was kept in a kitchen on a
shelf 5 feet from the floor, and not more than 6 feet distant from the
stove. Here they were subjected to the action of artificial heat through-
out the entire period.“ The seeds under ** basement” conditions were
kept ina small cellar, which during the season of L900 was very moist.

Auburn, Ala.—The seeds were sent to Auburn on February 17,
1900. The first complete set was received in return on May 30, the
second on November 19 of the same year, or after L102 and 275 days,
respectively. ‘* Trade conditions” consisted of an office room connected
with a greenhouse, with the doors frequently standing open; ‘* dry
room” conditions were obtained in the culture room of the biological
laboratory 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 humidity.

Baton Rouge, La.—The seeds were sent to Baton Rouge on February
17, 1900. On June 18 the first 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 by 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 buildings. A storeroom in the basement of a
private residence, having two sides walled with brick, furnished
** basement” conditions.

«Presumably these were in a dry place, but further evidence showed that the pre-
sumption was erroneous. The vapors arising while cooking was being done on the
stove gave rise to conditions very detrimental to a prolonged life of the seeds.

25037—No. 58—04——4

5O THE VITALITY AND GERMINATION OF SEEDS.

Wagoner, Ind. T7.—The seeds were sent to Wagoner on February
17, 1900. The first series was received in return on June 23, after 126
days; the second set was returned after 238 days, on October 13, 1900.
The sets for ‘trade conditions” were kept ina 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.

Durham, N. H.—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 buildings.
The door.opened into a hall, which led into office rooms, the chemical
laboratory, and the basement. An office 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 Arbor, Mich.—The set of samples placed under ‘‘ trade condi-
tions” was kept in the botanical laboratory, being 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 18, 1900,
until May 12, 1900, the set of seeds under ** dry room” 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 43° 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 laboratory, where they remained until vitality tests were
made. ‘* Basement” conditions were found ina fruit cellar, having
two outside walls anda 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 GERMINATION 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, respectively. From these results
the average percentage of loss in vitality has been calculated, reckoning
the germination of the control sample asa standard. It is thus a very
simple matter to compare the relative merits of the different methods
of storing and the role they play in promoting the longevity of seeds.

COMPARISON OF METHODS OF STORING AND SHIPPING. a

Taste XII.—Percentage of germination of beans subjected to various conditions of storage
in different localities.

[Germination of control sample: First test, 98.7 per cent; second test, 98.7 per cent. ]

Percentage of germination.
Num- ae Tae.
Pines offstorace Order of | ber of She hae Dry rooms. Basements.
ech heaStoL ican fe tests. |days in ES
storage.) aig | ate a eee | —<
Envel- Bottles. | Envel- |Bottles. Envel- |Bottles.
opes. opes. | opes. |
Wake: City hla sen ceeecte em cs sees WOUrStioais 129 | 98 98 98 98 86 98
DO oe ee ee Bee Sete ata bicict. Second . 234 S4 98 96 98 0 100
FACIL DUIS Al Qa autre act wate csmeme Hirst.c-2 102 98 97.5 100 100 97.9 97.5
DI) Ohneneee sooo eee emasmetssc Second . 271 DO 98 94 98 66 100
IMO DITO SA awe eat cate soc cls sinwiaae First. =<. 140 | 58 96 82 100 0 100
1) OMe ten seinen aeccase Second . 262 0 90 0 98: dikecccese 98
Bae toneROuce. as <a.coe-~ccece kes Birsto.c- 121 96 100 92 100 Ad 98
WO s sc seeeeaadcemeec cece Soc ee Second . 247 | 60 96 28 100 0 98
ELIS UAT beet Evistclote s:ecerararste ato cimeiafee Furst... 131 | 100 HOOT NE eee bee el ee ennemened Ee eve
ND Onset ticee: eee cs ces 2 Second .|........ 96 OS Me eee =| aces see ei es cea tsscars cate
Wiaronen imdl Pasi: scce cess ont First... 126 | 96 96 98 100 100 98
WOWsera st aie ccc cess cis.e'ces5.5 3 Second . 238 | 82 OOH Clececeess 100 S84 98
Minha Ne Hse cec ss scescccce ses Wirsts.2- 147 | 100 100 100 98 | 100 | 100
WOWeMe see ot acces ce eke aes Second . 251 78 96 98 96 92 98
ANINGATDOLMACh S252 Jckas Geen oe insta t=) 5 aces 98 84 98 $4 98 92
Ogee cesecececetoceeaestnen tec Second .].......- 100 100 | 100 91.5 92 | 100
Average percentage of ger- |/First.... 128 | 93 96.44 | 95.43 | 97.14 | 66.99 97.64
mination. {Second . 251 | 69.50 | 97 | 69.33 | 97.36 | 55.66 98. 86
Average percentage of gain |{Virst.... 128 5.78 2.29 aval 18.58. [32:13 1. 06
. : : ; e ec s | Ae . >
or loss in vitality. [Second . 251 | 29.59 1.72 | 29.76 1.36 | 43.61 | +0.10

The beans at Mobile 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, but the result of the first test of the same series
indicates that some moisture passed through the cork and that 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 247 days, for beans that germinate only 60 per cent are of no
value for planting.

The ‘‘trade conditions” at Auburn, Ala., and Durham, N. H., were
also very unfavorable to the prolonged vitality of the beans. At
Wagoner, Ind. T., San Juan, P. R., and Lake City, Fla., there was a
marked deterioration, yet not sufficiently great during the time given
to render them worthless for planting. However, it is quite evident
that beans subjected to such conditions of storage would not be fit for
planting the second season.

A summary of the table shows that the vitality of the beans 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 29.59, 29.76, and 43.61 per cent,
respectively, for ‘‘trade conditions,” "*dry rooms,” and ‘* basements.”

52 THE VITALITY AND GERMINATION OF SEEDS.

Taste NITI.—Percentage of germination of peas subjected to various conditions of storage
in different localities.

[Germination of control sample: First test, 95.3 per cent; second test, 95.7 per cent.]

Percentage of germination.
Num>=| Sense tay is la.
BINGO etorare Order of | ber of a rade cougt Dry rooms. Basements.
= BIOTEC: tests. |days in ice
storage. ] y
Envel- .¢ | Hnvel- .¢ | Envel- ¥
opes. Bottles. opes. Bottles. opes. Bottles.
Dake: Olby, Plate ost oes deen eee te ArSte ees 129 96 97.9 94 94 96 98
DOs semen soe cminece ana Second . 234 86 98 92 92 6 98
ATID Ut WAU 8 eee re eee Hirstate. 102 | 93.3 94 87.8 97.8 93.9 94
IDO ceseee eee SoS oe betes Second . 275 97.9 94 90 96 86 95
MobilevAla aoc eee aac nes Rirst=-. 140 | 69.2 92 88 96 10. 2 98
DOs Soh se eae eile Sao cee Seer Second . 262 | 44 _ 100 42 962 VE Soence 98
Baton Rougeslsa,.°2. 2245-22-52 First... . 121 | 94 | 92 94 90 90 98
DO ce ee aa fetes ooo eon Second . 247 80 88 70 98 0 98
SaniJUanvPwR ceeescc see eee | Hirst-22: 131 | 94 LOO) (Sass ores flepterctocnsye'| sere ee oe eeeetee
1 Be eke Oe Se es ae re | Second)... s-c22 98 98h 1 eae soe aeeeee | se eee |e eae
Waconer Ind. stones oaceee Hirst=. -- 126 | 98 90 96 92 90 88
DOR st emeaste setae scenes ees Seeond . 238 80 PAR Wr) Bree 96 88 92
DUH aN, see see see ee oe oe | minsteees 147 | 98 94 100 98 94 98
DO eee ee ee ae eee see Second .~ 251 94 98 94.7 96 v8 90
AnnevATbOr Michio 2 2..g22 sexes oc Hitsteseclaeee ese 90 O4 94 ie 96 94
ID) Oaeeiciestdep see cetoee ores eee Second 2) 2.222222 98 94 94 92 86 100
Average percentage of ger- | { First. ees 128 91, 56 94.24 93.4 91. 41 81. 44 95.43
mination. '|Second E 251 | 84.74} 95.25 | 80.45 | 95.14] 60.66 96. 28
Average percentage of gain || First ee 128 3. 92 ne bs 1.99 4,08 14. 55 +0.14
or loss in vitality. |Second - 251 | 11.45 0.47 | 10.94 0.58 | 36.62 | +0.60
|

The peas retained their vitality much better than the beans. How-
ever, the greatest loss in both peas and beans was in the envelopes at
Mobile and Baton Rouge. Some of the samples from the envelopes
germinated fully as well or even better than the control, but the gen-
eral averages of the second tests for all of the localities show a loss of
11.45 per cent in ‘trade conditions,” 15.94 per cent in ‘‘dry rooms,”
and 36.63 per cent in ‘S basements.” The beans under identical condi-
tions lost 29.59, 29.76, and 43.61 per cent, respectively.

The seeds kept in bottles deviated but very little from the standard
of the control.

COMPARISON OF METHODS OF STORING AND SHIPPING. 53

Taste XIV.—Percentage of germination of cabbage subjected to various conditions of
4g , { ,) ,
storage in different localities.

[Germination of control sample: First test, 92.7 per cent; second test, 92.4 per cent.]

Percentage of germination.
Num- :
- | Trade condi- ;
Order of | ber of : Dry rooms. Basements.
Tae = . ’
Place of storage. tests. \days in | tions.
storage.) an? 3 I a
Envel- ie | Envel- .< | Envel- a
opes. Bottles. opes. Bottles. opes. Bottles.
ake, Citys Wate se too esac. sean APRs oa: 129; 89.5 92.5 89.5 94 86.5 90.5
1) Ce ee aes eae a ciere ercjacit nie Seeond . 234 | 63.5 89.5 81.5 89.5 14.5 94.5
PATI DUT sAl Wears. soe bcocese eae First. ... 102 | 91 90.5 89.5 81 92 | 91
DO ee cecna ete ees ceemwe ssc. Second . 275 61e5. 90 90 89 60 85.5
MODE A a a eeiceessecee mac ce aoe - Hirst.3.- 140 | 64.5 93.5 58.5 96 58.5 92.5
1D YO) th epee eed Ae Reine RO Second . 262 | 17 87.5 5 95 Speuokest . GE
Baton ROUSC MIA sts2 5. cece ones 222 First... 121] 88.5 | 93 90.5 | 91 79.5 | 94
WOR ze cri cose ae ee tios canes Second . 247 25.5 90.5 11.5 86 0.5 90.5
(S{DV aid (LOE oT 2 5 0 Hirst-c.. 131 | 82 CS gS | NS aera ey arse pe (Pm Oo tte (ener
1BYO). 5532555 ae ee eae Second) s\en sac 76.2 Stet ead | | Sarees 3 2 PE ae ee ee <2
\aifivexave yc) ine] Bats [SM Weegee eee [irate s-- 126 | 83.5 93 94 95.5 88.5 97.5
DO eSeee os. 2s nce ees Seeond . 238} 70.5 Css | | Moen Ee 92.5 76.5 | 89
Mum ams Ne Hiss sees dane neces First....| 147] 98 97.5 | 89 96 95.5 | 94.5
1D Yn yes ee as ee nen eee ere Second . 251 1, 92.5 93 95.5 92.5 | 96.5
ATINGAT DON AMICK! <5 26.055.5 24.25. BITSt sl besar cee 96 92 94 90.5 89.5 94.5
TY ete ele ee Satie se ars ei csas ove aisis | Second .|........ 91 94 88 82 76 95.5
Average percentage of ger- {First i ache 128 | 86 93. 47 86.43 | 92 |) 84,29 93.5
mination. Second .| 251 | 52.15 | 90.56] 61.5 | 89.93 | 53.33 | 92.21
Average percentage of gain {First joss, 4 128 7.23 | +0.83 6.77 0.86 9.07 | +0.86
. . . ec a laled |
or loss in vitality. Second . 251 | 43.56] 1.94] 33.44] 2.67] 42.29] 0.22
|

Table XIV shows that the cabbage, like the peas, was injured to a
less degree at Mobile and Baton Rouge than the beans, but even the
cabbage seed kept in the paper packages in these cities were all but

killed.

cabbage than in the beans.

The average degree of injury, however, was greater in the
Ina 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, Fla., should be expressly noted.

The seeds kept in the bottles deviated but little from the control,
while those kept in paper packages germinated only 52.15, 61.50,
and 53.33 per cent for the trade conditions, dry room, and basement—
equivalent to a loss in vitality of 43.56,

respectively.

oOo

Oo.

44, and 42.29 per cent,

54 THE VITALITY AND GERMINATION OF SEEDS.

Tasie X V.— Percentage of germination of radish subjected to various conditions of storage
in different localities.

[Germination of control sample: First test, 83.6 per cent; second test, 78.8 per cent.]

Percentage of germination.
Num- : a
. > di-
Place of storage Order of as of apaaecon di Dry rooms. Basements.
te tests. |daysin in
storage.) mn =] es
~ | Envel- sc | bovel-'|,, 4.4. | Envel-
opes. Bottles. opes. |Bottles. opes. Bottles.
hake CibywWlaevccs esac eceee Hirsttse 129 79 78.5 84.5 7D 66 83
DOyanes eet. 2 a ae Second . 234 | 58.5 64 67.5 7 Ale3) 48.5 67
AMDUPT SAU Sia. sont aoe oe se HITSt ss =- 102} 75.5 85 85.5 80.5 86.5 85.5
DOs wen tees Sea Nee Senee ee ee Second . 275 | 63 71255 66 73.5 60.5 76.5
Mobile: Ale scence cis scwee eee MiTrsi aoe 140 58.5 81 HOA 81 75 76
DOL Seniesa c ee eet Seeond . 262) 51 yjalatsy 49 Ok alee aes 2,
BatonuRoure: a 2. ses escsesee PArStass 121 hed 89. 5 73.5 78.5 61.5 78.5
DO) Se oan ee ae ee etenronie a eeeere Second . 247 55.5 69.5 49.5 74.5 6105 75
Sannin PAR eeboe oo ane cere Firsts=-- 131 64 81559) nace qaelese ce el Seno. S| Soe
DOW aoe See reese. oe Second :|:=--225- 62 13209) )|eecscces 1S sano | ee ees |
Wagoner; Inde. 5 c.s% scceiciecce = Birstsi:- 126 | 77.5 80. 5 79 84 80.5 86.5
| D0 SY chee ere ee ee eee Second . 238 60.5 TERE HISAR Seese 77 63 70.5
Durham Nie ceeses.cese cote cs ee Firstsac- 147 | 80.6 DD 76.5 85 81 74
DOE Le cess SO eaeeeces Seeond . 251 59.5 81.5 74.5 85 68 79
Anmnesrpor Michi: 2-222 sr scene WiTSb= 5-2 see eee] 82.5 85 82.5 79.5 78 82.9
DOW cee Stivetrn cc eteaeseeeees Second 2)zs82e2-< 77.5 80.5 79.5 67.5 62.5 78.5
Average percentage of ger- [First.... 128 74.39 $1. 56 76.86 80.5 75.5 80. 91
mination. |Second . 251 | 60.94] 73.56 | 64.33 | 72.71 | 59 74.07
Average percentage of loss |{First..-- 128 | 11.02 2.44 8.07 3.71 9. 67 3. 22
|
in vitality. [Second .| 251 | 22.67] 6.65] 18.37] 7.73 | 25.18 6

The results of the tests of the radish seed are very similar to those
of the cabbage; the latter, however, showed a greater loss in vitality.
As shown by the second tests, the average percentages of deterioration
of the cabbage seed which was kept in the envelopes were as follows:
Trade conditions, 48.56 per cent; dry room, 33.44 per cent; basement,
42.29 per cent, while the loss in vitality of the radish was only 22.67,
18.37, and 25.13 per cent, respectively.

COMPARISON OF METHODS OF STORING AND SHIPPING. bd

Taste XVI.—Percentage of germination of carrot subjected to various conditions of storage
in different localities.

(Germination of control sample: First test, 83.8 per cent; second test, 82 per cent.]

Percentage of germination.

| opes. ‘Bottles. opes. Bottle 8.| opes. Bottles.
Make: Clty Was ..o2e. Js Soc S0c s First... 129 | 76.5 83 78 78:0° | 78 77.5
1 DY) ayes caps eee eee ar | Second . 234 AS. 5 80.5 67.5 718s 3 S4.5
(AITOUTM Ala: 25 23 5- o. Scsco020 4. <5 Hirste.<. 102 84.5 82 83 86 86.5 86.5
LYS SR SIS a ge a Second . 275 36 76.5 72.5 76.5 47.5 82.5

Mo pilenAlleeeee-woese ee oo) Stel. First....) 140] 59 87.5 | 51.5 | 83.5 | 20.5 87

WOM 28a ee eae suis csc o nes. Second . 262 8.5 86 ai) (1 il ene ee ee 7s
Baton Roure: Wassscc. .c.cccc acess HITSt 2c « | ial 74.3 82.3 75e1 86.8 57.3 82.3

mp c

1D Yo ge ein Se ee ee ee Seeond . 247 25 72.5 6.5 52.5 0 39
SiH a fq eon 0 ke eae! 6 a First... 13 71.5 OAaie Poch tects de eane| tele ceed Ameo
MO pees eo eras Sais aistaieie lea PSeCOUd = |Souecec 48.5 Gr Dm ei ene | ole oso nie, eal eee

Waronerm Inds. o2s.2 os ce ceck ss Hirst... 126 | 81.5 82 vie) SI Teh 87.5

1D 0) ea = eee ee ee Second . 238 | 49 Ried nlessecce. S1 45,5 S4
MIM AIMINN GE teaecaccccsens cn Birstece. 147] 78 82.5 S41 85.5 83.5 82.5
1D /0).nx ee, ae ae es ke Second . 251 2 85.95 87.5 85.5 12 87.5
ATIMEAT OOM MLGHE 2 sala a stars a/s;caio-s = BPS Usa jee< socio 76 79 83 75.5 78 ) 83.5

Table XVI shows results very similar to those of Table XV, except
that the carrot was affected slightly more than the cabbage. There
was also a greater falling off in the case of the seeds kept in the 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 Mobile and Baton Rouge. The
average results of the germination tests of the seeds kept in packages
are quite low for the carrots. Seed from trade conditions germinated
37.31 per cent, from basements 37.67 per cent, and from dry rooms
53.83 per cent, with a loss in vitality of 54.5, 54.06, and 34.36 per
cent, respectively. Under similar conditions the cabbage lost in vital-
ity 48.56, 42.28, and 33.45 per cent, respectively.

THE VITALITY AND GERMINATION OF SEEDS.

Taste X VII.—Percentage of germination of ‘A’? sweet corn subjected to various condi- i
tions of storage in different localities.

[Germination of control sample: First test, 92.7 per cent; second test, 92.4 per cent]

Num-

Order of | ber of

Place of storage. tests. |daysin
storage.
Make! City MPlas 2.222% ses sscecacees Hirstssce 129
1D Yo Ss Re ge ae CRE Second . 234

ATI DUTT IA ae oe 8 nw ees eee oe Rawste. se 102
DO nce et Eons ie cece 2. SA Second . 275
IMObile: Alar eos e se cceek cera Harstoeee 140
IDO ek access a. neces Second . 262
Baton Rouge! hae. .ce-essose2 =e Birsts..- 121
DO Seem ce Soo eee seeeeee nce | Second . 247
Son Jan Peas secestse cet aye Mitstsece 131
DO ie sa eee Se ee taistestae laeec sce Second: <|2=-2 22.7
Waroners Inde Wl ee see penne PUTSt seals 126
POPS A Se eee s sale ee Second . 238
[Doigatherpl tees eee eR a ae Hirsi sees 147
DGS stecaseccs sos teclenoeeh eee Second . 251
AnnoATbOYs.WiCh: < soe kee cere arate BYTSE eel aces
DO oes Soca eek eee ae cease Second’ :|2.2-o2<5
Average percentage of ger- |{First.-.. 128
mination, Second . 251
Average percentage of gain {First. ae 128

or loss in vitality. |Second . 251

Percentage of germination.
Trade condi- i :
one Dry rooms. Basements.
Envel- Envel- Envel- :
opes. Bottles. opes. Bottles. opes. Bottles.
|
94 96 94 92 88 98
92 100 96 90 54.5 100
96 98 94 98 100 92
88 98 94 90 80 100
80 100 80 96 94.1 96
20 96 26 100 | Sse2see 96
96 94 96 88 86 100
88 96 88 96 14 100
96 || Oe Paneer lester isscobsos
92 Qh el accel saeco seem teats
96 98 94 96 96 96,
90 OG) Bilaeaeess 96 92 94
| 100 92 95.9 90 100 96
96 96 96 96 100 98
100 86 94 89 100 96
98 98 100 96 92 98
94.75 94.75 92. 56 94. 14 94. 87 96.29
83 96.75 | 83.33 | 94.86 | 72.08 98
+2.21 | 4+2.21 0.15 | +0. 01 2.34 +3. 87
10.11 | +4.71 9.81 |} +2.66 | 22 +6. 06

Tarte X VILI.— Percentage of germination of ‘‘ B’’ sweet corn subjected to various condi-

tions of storage in different localities.

[Germination of control sample: First test, 89.8 per cent; second test, 88.5 per cent. ]

Percentage of germination.
Num- F
Noa - | Trade condi-
yeas a Order of | ber of A Dry rooms. Basements.
Place of storage. tests. |daysin tions. y
storage. E 1 E 1 E 1
Envel- a nvel- , nvel-

opes. Bottles. opes. Bottles. opes. Bottles.

AES City aeccssn eh. see aoe Hirst-...+ 129} 86 60 90 38 76 46

1 Ds Sens eee pe pare ty se ee Second . 234) 77.1 2 64 0 30 0

ATbUrn AS eee ccee cee een ee BiTrst=s.. 102 | 88 92 86 86 86 84
DOst 5 sees asec ee ener Second . 275 62 56 82 38 82 $9.6

Mobile Ala).cc2cosa2 saeco sce irstvs.- 140 48 81.2 60 87.5 75 86

DO ees bak bee Se eee eee Second . 262" 12 52 16 64 iy Ese 76

Baton Rouge; Udi seccscsase- eee First... - 121 | 80 82 S4 94 64 88
DO soo. ad come oe patentee Second . 247 | 54.2 36 66 46 4.5 61.2
San UMA wes Reo oe oe nar eeetene eee Mirstse=- IDA) 72 yp Raa eee iy eo celle Net
DO con oc ceeeee wend Seen eee Second’ .|2--5--c- 78 FAST. | ch osleck Senses ee se sece=s ee eeeeee

Waroner mois. cen baat eee ce First... 267 ese 82 90 88 84 84

Oa ot ee oee te eeen eee Seeond . 238 | 78 LA — ge oe 88 88 76

Durham N. A ool sost Sees cece Binsts==- 147 | 89.3 69.5 84.2 83.6 80 SO

DO pee eee se eee cee een Second . 2611 82 91.8 84 88 76 88

‘AMD VATDOT MIC ce: oe soe eens Mirsts 3. s|sesse-e% 92 88 88 48 88 96

DOs Sa chee eat ee ea Second e|-on-aoee 80 92 86 22 82 88
Average percentage of ger- |{First.... 128 | 78.16 | 78.381} 83.17} 75.01 | 79 80.55
mination. Second . 251 | 65.41 59.70 | 66.33 | 48 60. 41 68. 40
Average percentage of loss |{First...- 128 | 12.47 | 12.31 6.87 | 16 11. 54 9. 80
in vitality. Second .| 251 | 26.09 | 32.55] 25.06] 45.76 | 31.74 | 22.71

en inspire CAs

COMPARISON OF METHODS OF STORING AND SHIPPING. iT

Tables XVII and XVIII have been considered together, since both
have to do with the same variety of sweet corn. The difference in the
quality of these two samples was quite marked when the seed was
received. Germination tests were made January 30, 1900, and showed
94 per cent for the ‘‘A” and 88 per cent for the ‘*B” corn. In
November, 1900, samples of seed from the same original packages
were tested, giving a germination of 92.4 per cent and 88.5 per cent
for the ‘‘ A” and ‘* B” samples, respectively, as shown in the controls
of the above tables. Thus, when two grades of corn are subjected to
favorable conditions of storage, both are well preserved; but when
subjected to unfavorable conditions, the one of poorer quality is much
more susceptible to injury. The ‘‘ A” sample which was stored in
envelopes in trade conditions lost 10.11 per cent, as compared with
26.9 per cent for the *‘B” sample. The ‘‘ A” sample which was
stored in dry rooms lost only 9.81 per cent, while the ** B” sample
lost 25.06 per cent. In basements, the ‘‘ A” sample lost 23 per cent
and the ‘* B” sample 31.74 per cent. In both samples the corn in the
packages stored in the basement at Mobile was so badly molded at the
time the second tests were made that they have been omitted from the
table.

The most interesting feature in comparing the results of these two
samples is found in the seed which was stored in the bottles. The
average results of the ** A” samples show a much higher percentage
of germination for those from the bottles than the control, while the
averages for the ‘* B” sample were much lower than the correspond-
ing controls. The average germination of the ** B” sample from the
bottles was 59.7 per cent for the trade conditions, 48 per cent for dry
rooms, and 68.4 per cent for basements, or a loss in vitality of 82.55,
45.76, and 22.71 per cent, respectively. This difference was due to
two causes, first, a difference in the quality of the seed at the begin-
ning of the experiment, and, secondly, the larger amount of water in
the second sample, ‘'B.” The greater quantity of water present in
the seed gave rise to a more humid atmosphere after the seeds were
put into the bottles, especially when subjected 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 seeds are put up in
closed receptacles; they must be well dried if vitality is to be preserved.

58 THE VITALITY AND GERMINATION OF SEEDS.

Tarte XIXN.—Percentage of germination of lettuce subjected to varicus conditions of
storage in different localities.

[Germination of control sample: First test, 81.6 per cent; second test, 92.3 per cent.]

Percentage of germination.

Num- Trade
ie Order of | ber of Nips es Dry rooms. Basements.
Place of storage. tests. |daysin conditions.
storage. E a 1 . ae 1 ae aay 1 ar ae
invel- .¢ | ENvel- .¢ | Envel- ae
opes. Bottles. opes. Bottles. opes. Bottles.
Dake Citys Wlaecss<<cseesseeectose Mirsts-=4 129 87 84 81 76.5 68 77
DO eee eet hoes se cee eee oe Second . 234 | 85 92 92.5 90 43.5 95.5
AMUIDUT Ale te. scence eee ee HITStes. 102 | &6.5 85.5 88.5 84.5 84.5 88.5
DOr eee eho tea ae eee eeeeee Second .} 275 | 86 90.5 90. 5 91 83.5 90
Mobile, Aloe ctecse eo eases eeetee Hirst ec 140 63 78 58 87.5 eA: 83
DO) sth Sie este kets cls eee Second -| 262 20 88.5 3l 90RD) eae ee 91.5
saton Rouge, las. 222.2.52-cscceee First.... 121 82.5 81.5 79 78.5 70.5 76
DOE ester ec nee Second . 247 84.5 93.5 74.6 87.5 a) 92.5
aM Ms Pee. cen mcoecas occtmie oe First... 131 | 79 S725 ie sakseed bance aewaeee |e ae
DoW e ee eee ee ree ee Second .|........ BBO A289 Vike ee ee el cere seen ree
Wagoner, Ind. T....-....... eee | First-223 126} 78 76 80 82 81 76.5
DOR Scat 5. eae ee cost cce ss | Second . 238 | 82 O25 Mies seen 94 87.5 89
Dima Ne dee seco. ot see ae First. :..- 147 82.5 80. 25 83. 25 77.5 80 done,
DO oe occa coe ae cee Second . 251 88.5 93 92 93 90.5 90.5
ATIMeAT DOT, mMiCMiee se oer = cee ee Mirsts=2 ales cscs 82 68.5 84.5 S15 78.5 ie
WOe et ahs Bose sees eee ane ore Second .|.......- 92.5 90 89.5 90.5 88 9155
Average percentage of ger- |{ First aise 128 80. 06 80.15 79.18 81.14 | 66.28 78.31
mination, {Second - 251] 77.75 | 91.12 | 78.33 | 90.93 | 65.58 90.78
Average percentage of loss |{First...- 128 1.89 By irs 2.97 .56 | 18.78 4.03
in vitality. [Second . 251 | 15.76 1.29] 15.14 | 1.49 | 28.95 1.65

The lettuce has shown no very marked deviation from the controls,
save the seeds from the packages kept at Mobile, and those which were
stored in basements in envelopes at Baton Rougé and Lake City.
The average results of the second series of tests show a similar loss in
vitality of all of the seeds from the envelopes. Thesamplesof seed from
the bottles germinated practically as well as the controls. The results
of the first series of tests are not entirely satisfactory, none of the
tests having 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 first series the ger-
mination tests were unavoidably made at 26° to 27.5° C. Neverthe-
less, this seeming objection is of little consequence, since all of the
results are directly comparable with the control.

aw ner =

COMPARISON OF METHODS OF STORING AND SHIPPING. 59

Tasie XX.—Pereentage of germination of onion subjected to various conditions of storage
in different localities.

{Germination of control sample: First test, 95.8 per cent; second test, 97 per cent.]

Percentage of germination.

Num- | , ‘
: appr | Lrade condi- ,
Order of | ber of : Dry rooms Jasements
D]< ad 7 Ss 2 - °
Place of storage. tests. |days in tions.
storage. ir lpia. ‘
~ | Envel-i,_ ig | Envel- |p, _| Envel- |, ’
opes. Bottles. opes. Bottles. opes. Bottles.
Lake City, Fla Hirst... 129 | 95 95 95. 5 95 | 80 97.5
Do Second . 234 16.5 95.5 79 96 | 0 97.0
J\iot ob id ogee dE Wes eae nee ne a First.... 102 96 96.5 96 98.5 | 97 97.5
TD Oar orcercie unio sterca dis love aes Second . 275 12 96 96 98 | 23.5 99
MIODUGHAIR (eee Sc cocnc sees tedaees Hirst... 140 i 94.5 11.5 96.5 7d. 99
1B X0 Yi Aine a es errs na Second . 262 0 94.5 0 96.5 ad 97.5
Batom Rouge; Lase.----2..----.-- First.... 121] 90 | 93 o4 93.5 | 35 96.5
D0 eS OSS Cee eee Seeond . 247 0.5 97.5 0 65 0 48.5
Me Ulan bmn vsticts = 20sec, ae alee cye.erse Firsts. 13 84.5 OR at eke neyo |heairettaeclliciok Sace sil eee
1 BX 05 ti, See ee eS ee a Second <|.......: 50 QGa en meee oe 2 less. cocclee anetan noeee
Wittoronver thes M2822 kee cles First....| 126 | 93.5 | 97.5 95.5 97 96 94,5
1DYS) 53 AR Aas cee Eee Sees Second . 238 ZO ECS Tee ames 97.5 34 97.5
MST New Ele. eo ec oie cee Bursts... 147 | 96.5 96 | 94.5 96 93 94.5
1D Yo, Sais a or Raa eee Sel ee a Second . 251 0 97.5 96 oy 4 |} 98
ATTIPAT DOM (MICH). ivceics oc.atjeeeeod MnSts 222 le so. se 95 96 99.4 97 93 97
ID (Pepe ee Sees nies Se esc oF Second .|........ 97.5 97.5 95 96.5 47 98
Average percentage of ger- {First.. As 128 82.19 | 95.81 83. 79 96. 21 81.36 96. 64
mination. |Second .| 251} 25.12] 96.25] 61 | 92.36] 33.08] 90.86
- |
Average percentage of gain | First... =| 128 14.20 | +0.01 12.53 |+ 0.43 15. 07 +0. 87
or loss in vitality. |Second . 251 | 74.11 1.20] 87.12] 4.80] 65.90 6.33
|

we Ths ee pa een included in nbing up ihe averages inasmuch as the eds were badly

The onion seeds which were stored in the envelopes were very seri-
ously affected in many 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 Baton Rouge were entirely killed. The seed from trade
conditions at Baton Rouge germinated only 0.5 per cent. In many
other cases the samples from the envelopes had become practically
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 Baton Rouge. These two tests have lowered
the average results quite materially. If they were not included the
averages would be raised to 96.91 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 74.11, 37.12, and 65.9 per cent, respec-
tively.

Onion seed is relatively short lived, and very easily affected by
unfavorable external conditions. For this reason onion seed should
be handled with the greatest care if vitality is to be preserved fora
maximum period. This may be done successfully by keeping the dry
seed in well-corked bottles, or in any good moisture-proof package.

THE VITALITY AND GERMINATION OF SEEDS.

Taste XXI.—Percentage of germination of pansy subjected to various conditions of
storage in different localities.

[Germination of control sample: First test, 68 per cent; second test, 53 per cent.]

Percentage of germination.
Num-
3 Trade
ae: Order of | ber of ane Dry rooms. Basements.
Place of storage. tests. |daysin conditions.
-. storage. :
Envel- Envel- Envel-
opes. Bottles. opes. Bottles. opes. Bottles.
LakerGity, Wat... 2. 22452 22 See2e Firstse-- 129 | 44.5 63 45 58.5 10.5 62.5
SO Sean oa ee eae ee ess | Second - 234 1.5 d4 22.5 47 0 57.5
SAID UI PAC frais ee seer eee | First.... 102) 57.5 68 66.5 62 60 59.5
Dope he et wate sciee tastes | Second . 275 2 20.5 28 27.5 0 33n0
Mobiles AN aso ak ete eee ee HiTsteeee 140 3 57.5 2 61 a! 59
DO Me 2 ae seen eee eee | Second . 262 0 20.5 0 2050) || |senecens 2.5
Baton) Rouge: a 222s--heescer acer | Hirst. 2. < 121 | 28.5 53 38 44 4.5 54
DO ae BA aa scare Second . 247 0 34 0 17 0 OED)
Sam Jian Ret = a eee eece Bins tee. 131 | 20 GOLD Si ssececacleckcccllseoeateeeleeseeetee
DOSE Ae oS ks RE Soe Secondyaliaeeceee 6.5 5 | eens Maeno beeriter esp aaaaS
Wagoner snd Mee ss-acceeeonee lenirsheee. 1Q6ueASsp: 61.5 50.5 62.5 46 59
ID) Oe te eee RECO Ga 238 qa i seats 59.5 8.5 b2n0
Durham wN eS oene cone eee ees | Birsteen. 147 55.5 66.5 49.5 63.5 49 63.5
OAs Se eh ne cs ce ee eee Second . 251 0 60.5 44 60.5 36.5 60
ATMeAT DOr, Michie. ssaes-seees see Birst=-ealaeeseece 53.5 51 59.5 40 50 53
Do weer. See aati oer Second .]........- 46.5 45 52 48.5 3.5 60.5
Average percentage of ger- |{First.... 128 | 38.87} 60.12 44743) 55.93 B1e57 58. 64
mination. |Second .| 251] 8 44.75 | 24.41] 40.80] 8.08| 38.438
Average percentage of loss |{First...- 128 | 38.3 4.67 | 29.48 | 11.23 | 49.89 6.92
in vitality. Second . 251 | 84.91 15.60 | .53.97 | ‘23.02 | 84.76 27.49

TapnLte XXII.—Percentage of germination of phlox drummondii subjected to various con-
Tg sy 7
ditions of storage in different localities.

{Germination of control sample: First test, 69 per cent; second test, 53.9 per cent.]

Percentage of germination.
Num- :
Trade condi-
oe be Order of | ber of F Dry rooms. Basements.
Place of storage. tests. | daysin tions.
storage. meee Paget? Envi 1 E 1
envel- .g¢ | Envel- Envel-
opes. Bottles. opes. Bottles. opes. Bottles.
Lake City, Blavecossceccsecesseseee First-.-- 129 | 41.5 78 62 62 20.5 77.5
DOM Sane eo te ee eee eee Seeond . 234 2.5 57 6 25.5 0 63
Auburn) Alga 2- 22S. esmee eee eee HirSte eee 102 61.5 W230 62 63 65.5 67.5
DO a2o5 oo tos aes oe eee Seeond . barf) 1 56.5 13:5 59 1 65
Mobiles Als,..5f2 4.0 ete eee Hirsts...! 140 0.5 5d 0.5 74.5 0.5 58.5
DO )0 2 Bis: Zee) Ee eee Second 262 0 51.5 0 Nha. |Leetesec 48.5
Baton Rouges Liaoa.. eo+ eee eae irstesn 121 47.5 62.5 A305 58.5 2 70.5
DO asec ase eee eee Second . 247 0 58 0 58.5 0 6L.5
Sani Jian’ (Piacoa cases see Buirstess- 131 23.5 C5 ytd Ssaerciociel Syeie seae |oe cine | Cees
DO eset teean efor 2 eee Second) 22. ste 2 11.5 615% Wisse cond Ss eo docel be aeeetss| eee
Waronert Ind phe 2. o5-ee eee Hirste--2 126 | 50.5 Bed 61 70 65 75
DOM oc PEAS Sock See eeloneeeee Second . 238 ah) 66% aces 57 9.5 47.5
Durbam’ INH ote eee eee eee Hirstes.; 147 67 74 62.5 45.5 69.5 led
DO wel ote e ce ccent Bo eee eee Seeond .~ 251) 0.5 62.5 33 30.5 45.5 70
Ann UArbor,.Mich\- ...2s2--ssseeees Mirstoeen Saas see 67 66 75.5 69.5 64.5 72
DO) sn 204 2 Ne cone. meee Second .|.......- 40 54 55 58.5 10.5 61
Average percentage of ger- |{First-..- 128 | 44.87 | 68.31 | 52.76} 63.28 | 41.07 70.35
mination. |Second z 251 7262)" 68y3i |) WOE 495645 ts08 59. 5
Average percentage of gain |{First..-- 128 |} 34.97 1 23. 54 8.29 | 40.49 | + 2.01
or loss in vitality. |Seeond - 251 | 85.86 | +8.27 | 66.78 7.91 | 79.45 | +10.39

COMPARISON OF METHODS OF STORING AND SHIPPING. 61

Pansy and phlox have been considered together, since their behay-
ior was almost the same. Both of the controls deteriorated to a con-
siderable degree during the 123 days which elapsed between the time
of the first and the second test, pansy losing 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 great. 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 66.78 per cent for phlox, and in base-
ments a loss of 84.76 per cent for the pansy and 79.45 per cent for the
phlox. These results are obtained by considering the second test of
the control as a standard, the depreciation of the control being dis-
regarded. Some samples were dead and many more were of no eco-
nomic value. It is especially interesting to note how quickly the seeds
died at Mobile, Ala., there being only a few germinable seeds at the
end of 140 days.

The behavior of the seeds in the bottles was more or less variable.
Some of the pansy seeds showed a higher vitality than the control, but
the averages were somewhat lower, the mean loss ranging fron 15.60
per cent under trade conditions to 27.49 per cent in basements, while
with the phlox the means for trade conditions and for basements were
higher than the control by 8.27 and 10.39 per cent, respectively.

Taste X XIUL.—Percentages of germination of tomato subjected to various conditions of
storage in different localities.

[Germination of control sample: First test, 95.5 per cent; second test, 97.5 per cent. ]

Percentage of germination.
Num- : [
Trade condi-
Order of | ber of : Dry rooms Basements
» Ee 3 oe 4 + A . .
Place of storage. tests. |daysin tions.
StOlaD Om GES g wr [emer eles
Envel- Bottles.| Envel- Bottles. Envel- Bottles.
opes. opes. opes. |
ISN Re Ol aed OE Ae Pitstesae 129 | 94 94 94 95.5 88.5 | 94
1D 0) is SS See eS Seer a oer Second . 234 |° 94 98 94 97.5 77 97.5
JN DUO BE bi See ee ee First... . 102 | 95 94.5 93.5 97.5 96 | 94.5
WOR Bea a. tok Oe. ue eee sees Seeond . 275 | 94 98.5 97 94.5 98 96.5
VIG [oil CMAN See See. <:crajsiarsicr sre Sisiave.notece Mirstass. 140 | 90 94.5 91.5 96.5 64.5 93.5
1X0) (OO ESS IESE eS eee Second . 262 | 79.5 97.5 87 95.5 19.5 98
BaAtLOnP ROUSE MLE 2. seen cecin-~ 2 << Hirstacec g AL es ped) 95 91 95 83.5 95
WO Peene ia sae ccececicadeses cs Second . 247 | 96 96.5 93 98 Beda 96
SATIMMAT MP MREAMer ores Suc8se ees Rurstess- 1316) Od eee ede DN |S ceece | ones oe eee ee ee eee
DO Ree eee ie ae meets iceteees Second .|........ 96.5 GP Bp. «| Bin es sine | eee te cell rece cae ses see
WACO EME T Cte Mae wants anrlacieatejce 3 FTSUS es 126 | 96.5 97 98 96.5 98.5 96
IDO) soos daece Cen Bee eee eee Second . 147 | 94 CSF) lascccuss 97.5 98.5 93.5
ID) Cnr ee NEE ae Sore aici js cwieteie saa Witstesss 147 | 94.5 95 97 94 97.5 96.5
1D) oa ee SOS ee nese aes Second . 251 | 87 98 97 99 97.5 97
FATITIBAT DOL MUCDi st ec acca ce seas bibs hes) Bee 89 94 93 91.5 89 92.5
Osteen sas emeceacbosceteece Second .|..:..... 98.5 9S 98 97.5 95 98
Average percentage of ger- { First. roe 128 | 93.06 | 94.81 S84 95. 21 88. 21 94. 57
mination. [Second . 251] 92.44] 97.31 | 94.33] 97.07 | 84.25] 97.21
Average percentage of loss |{First...- 128 2.56 0. 72 1.57 0.3 7.64 0.98
in vitality. \Second.| 251] 5.20] 0.20] 3.29] 0.44] 13.63 0.30

62 THE VITALITY AND GERMINATION OF SEEDS.

The tomato seed, as shown in Tables V and XXV, was the most
resistant to the unfavorable 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 ina 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, 13.63 per cent.
The average percentage of germination of the seed which was kept in
the bottles differed from the control less than one-half of 1 per cent.

Tabie XXIV.—Percentage of germination of watermelon subjected to various conditions
of storage in different localities.

[Germination of control sample: First test, 95.5 per cent; second test, 99 per cent.]

Percentage of germination.
Num- ee ean: ae :
Place oF slomise Order of | ber of CO Dry rooms. Basements.
Ca re tests. |days in a
storage. ea)
Envel- ,< | Hnvel- iq | Envel- a
opes. Bottles. opes. Bottles. opes. Bottles.
hake City) Mlascnoss-s cose mao. First... 129} 98 98 96 98 98 100
DOne=e hare aae =< eee eae oes Seeond . 234 92 96. 2 86 98 70 94
ATIDUIN Alacss eee ean ene cee eee Pirst.s.< 102 | 94 94 96 98 99 100
1) Oe PE eee ccs Sea Sener Seeond . 275 | 86 100 98 98 94 96
MODE MAIS ck oeactenscsscweasnaes Hirstosss 140 98 98 98 100 80 100
TG, = chee oot Soe ewes ecco Second. 262 64 96 68 96 0 100
Baton houre: baseceoese- sone. so Hitstoece 121 | 100 98 96 | 100 98 98
DG ist oc koe ate ote Lok eae e sass Second . 247 92 98 86 | 100 20 100
San UameiPs Roses. es5: cence. es First....| 131 | 96 LOOEIR® (222288. 20.20.
WGics feceecec kad eeseces a cce S@CONG clesacucc 88 LOO! @ yee see Naccme see ||eeoeoes sees
Waconer ind (hoa eee cece Kirst... 126 98 98 98 | 100 96 98
DO easter an ae ee eases Second . 238 94 OS Weecceees | 96 88 98
SUD at Ne ceeseeacces oeeacclek Hirst. ... 147 98 98 100 98 98 96
DS rete oscne eee icia ee cetayae oe Second . 251 82 96 98 92 94.1 98
Ann Arbor, Mich ................. Hirst cqces sce 100 100 94 94 98 96
DOES. pemece aes ceca ceesemtes SeEconG elo-s- cee 96 | 100 96 92 100 96
Average percentage of ger- {First eile 128 97.75 | 98 96.86 | 98.29 | 95.29 98. 29
mination. |Second 2 251 86.75 | 98.02 | 88.67 96 77.70 97.43
i | |
Average pecentage of loss {First.... 128 0. 56 0.31 1.47} 0.01 3. 06 0. 01
in vitality. |Second " 251 12587. 0.99 10, 44 3.03 | 21.52 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;
88.67 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 per cent, respectively, as com-
pared with the 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 very marked in some of the more critical localities, particularly

COMPARISON OF METHODS OF STORING AND SHIPPING. 63

et Mobile. However, the greatest loss, as shown by the germination
tests, was during the 123 days immediately following.

While seeds, like other living things, are capable of withstanding
quite unfavorable conditions for a considerable time without showing
any appreciable 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 differ-
ent in the different places. The conditions at Mobile, Ala., proved 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 effect of climate on the
vitality of seeds. The results are tabulated on pages 18 and 23 and
represented diagrammatically on page 24, so that 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
vitality 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 basements—in both envelopes and bottles.

Naturally, the results of the second tests are of the greater impor-
tance, and, in order that the results may be readily compared and more
critically examined, they have been collected and tabulated herewith:
Taste XX V.—-lrerage percentage of germination and average percentages of loss im

vitality of the different kinds of seeds when kept under different conditions.

at Trade conditions. Dry rooms. Basements.

OP tan a aaa Pee i . a

A Envelopes. | Bottles. | Envelopes.) Bottles. Envelopes. Bottles.
oO —- fs = ey | ee z = a == 7 a

|S 2 ia oa ia 4 ba

Kind of seed. & a = d aS S| Ho a = | — a a

2) ios} ° ios} ° os] fo} a (o} 3 2) oC

rs = se = re! — 4 aa Be = Be} 3S

ra - 3 - 3 > 3 - 3 - o -

= = a a S| = a = q - S| a

bs | = | Am | a = ‘fe = 45 3 =|

Elealilgi-£ieti|#ile)2ile|él eg

o o} o ° o ° ov (2) v ° v °

, 4s) 4 oO a oS = o Hn id) 4 o A
MOMPBtOs ss) San oe. 97.5) 92.44) 5.20) 97.31) 0.20) 94.33) 3.29] 97.07} 0.44} 84.25) 13.63) 97.21) 0.30

i}
Sweet corn, ‘°A’’..| 92.4) 83 10.11] 96. 75}+-4.71) 83.33] 9.81] 94. 86}+-2. 66} 73.08} 22 98 eo 6.06
GAS ose atc. 95, '7| 84.74) 11.45) 95, 25) 47 80. 45} 15. 94 95.14 . 58} 60. 66) 36.62] 96.28/+ .60
r | |

Watermelon......- 99 86.75) 12.37) 98.02 . 99} 88.67) 10.44; 96 | 3.03) 77.70) 21.52) 97.43 1.59
WettuGer..cass0.s2 92.3] 77.75] 15.76) 91.12) 1.29] 78.33] 15.14] 90.93} 1.49] 65.58) 28.95) 90.78} 1.65

Raggi. =. ofcss a0 78.8} 60.94} 22 67 73.56] 6.65] 64.33] 18.37] 72.71) 7.73] 59 25.13] 74. 07 6
Sweet corn, ‘“B”’..] 88.5) 65.41] 26.09} 59.70) 32.55} 66.33] 25.06) 48 45.76 60.41) 31.74) 68.40) 22.71
BOBS oss 3- hee ees 98. 7| 69.50} 29.59] 97 1.72! 69.33) 29.76) 97.36) 1.36! 55.66) 43.61) 98.86, +.10
Cabbage 22. esc. 92.4) 52.15] 43.56 90.56) 1.94] 61.50) 33.44] 89.93) 2.67) 58.33) 42.29] 92.21 - 22
Carrols sss8ssee-55 82 37.31] 54.50; 80.87} 1.38] 58.83) 34.35) 74.71) 8.89) 37.75) 53.96) 75.21 9.50

é |
ONTO = she ace ina 97 | 25.12) 74.11) 96.25) 1.20) 61 37.12) 92.36) 4.80) 38.08) 65.90) 90.86) 6.33
| | | |
PaNISY: oo sss see 53 8 84.91] 44.75) 15.60] 24.41] 53.97] 40.80] 23.02] 8.08] 84.76] 38.43] 27.49
| |
121011 00)>. coe agp = ee 53.9) 7.62) 85.86) 58.37 +8. 27) 17.91) 66.78 49.64, 7 M1 11.08) 79. 45} 59.50) +10. 39
| is
Average loss | | | |
‘ aad: | -
Ie VLbAIGG Ye eee S| eee USSU S| GS err | eI ols) ae bt SN OS lice aaa 42: 28]. sacc - 4.51
| | | aed

64 THE VITALITY AND GERMINATION OF SEEDS.

In comparing the average results shown in Table X XV, it will be
seen that different seeds behave very differently under practically iden-
tical conditions. The list of seeds has been arranged according to
their loss of vitality as represented by those kept in envelopes under
trade conditions, as shown in the fourth column. The tomato seed
gave a loss in vitality of 5.20 per cent, being the most resistant to the
unfavorable climatic conditions. Phlox, on the other hand, germinated
only 7.62 per cent, representing a loss in vitality of 85.86 per cent.

Likewise the same seeds behave very differently under slightly
different conditions, as will be seen by comparing the percentages of
deterioration in the case of seeds kept in envelopes under trade condi-
tions, in dry rooms, and in basements. In dry rooms the order, except
the peas, is the same as for trade conditions. The loss of vitality in
the seeds stored in the dry rooms was uniformly less than for those
stored under trade conditions, excepting for the peas and beans; but
in the series from the basements there was great irregularity. The
loss in vitality for the most part was uniformly greater than under
trade conditions or in dry rooms save in the last five—cabbage, carrot,
onion, pansy, and phlox—where the loss was less in the case of those
kept in the basements. This indicates that these five species of seed
are less susceptible to the evil effects of a moist atmosphere when the
temperature is relatively low.

The relative value of these three conditions for storing seeds in
paper packets is best obtained by a comparison of the general averages,
The average losses in vitaliy for the thirteen different samples of seed
which were kept at the eight different stations were as follows: Trade
conditions, 36.63 per cent; dry rooms, 21.19 per cent; basements, 42.28
per cent. From these results it is quite clear that seeds put up in paper
packages will retain their vitality much better if keptin dry, artificially
heated rooms than if they are subjected 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 but little deviation
from the control samples, and many of the samples germinated even
better where the seeds were kept in bottles. The ‘‘A” sweet corn
offers the best illustration of the increased germination. 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 differently
when kept in bottles. This difference in vitality is directly attributed
to the greater quantity of water in sample ‘* B,” showing the necessity
of thoroughly drying seeds if they are to be put up 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 preserving the vitality of seeds. Under trade
conditions the loss in vitality was 86.63 per cent in envelopes and

EXPERIMENTS IN KEEPING AND SHIPPING. 65

3.93 per cent In bottles; in dry rooms, 21.19 per cent in envelopes and
8.08 per cent in bottles; in basements, 42.28 per cent in envelopes
and 4.51 per cent in bottles.

The necessary precautions to be taken, if seeds are to be stored in
bottles, are (1) a well-dried sample, preferably artificially dried seed,
and (2) a cool place for storing, at least a place in which the tempera-
ture will not be higher than the temperature at which the seeds were
originally dried.

If the above precautions are taken at least two beneficial results will
follow: First, protection against moisture, which is of considerable
importance, as many seeds are soon destroyed in that way when kept
in paper packages. Secondly, vitality will be preserved for a longer
period and consequently 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 vitality in warm, moist
climates much better when kept in bottles than when kept in paper
packages, the necessity of finding a more suitable method for sending
small quantities 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 inconvenience and expense involved by this method of putting
up seeds. The increased cost of bottles, as compared with the paper
packets now so universally employed, the additional labor and expense
necessary to put up the seeds, the greater cost in handling and pack-
ing the bottles to insure against losses by breakage, and the increased
cost of transportation, are all matters of vital importance. 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, pansy, and phlox.4¢

@The lettuce, onion, pansy, and phlox were from the same bulk samples of seeds
~ as those used in the earlier experiments; but the beans, peas, and cabbage 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 experiments 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 these samples were first dried for ten days in an incubator main-
tained at a temperature of from 30° to 32° C. The amount of mois-
ture in the samples before and after drying, as well as the moisture
expelled during the drying process, was as follows:

Moisture test of seeds in special packages.

Kind of seed, ‘airdiied | Moise | Moise
Per cent. | Per cent. | Per cent.

B@ans 52 Bis fice Sap BSS Se eiwielora chats Seralarsinve sass Safar s csimeceeisinie a oats sisters 10. 32 | 4.90 5.42
PGBS Sra od deca e oe ces ase EAE ees tan awe seas casas ee acces 9.70 | 6.00 3.70
(OF 10) of: 04 oh Pee ie, SR ec Sia ee a ye ee A ei eed a nee See 4.89 | 3.47 1.42
Lethe s2o5 64.28: ot ao ae Sere Sete es Se cameos eet erie See eeneetas | 5. 33 | 3.80 1.53
C10 C0) «eee sr ecg ee eR OE MR at EE SS Aen See er IE aS Io 6.48 4.47 2.01
PSY ices Sete a epee een Seay pate ets ey ara age mee Can hee to clahela enter siete tatrtar cic 4.82 3.13 1,69
PHIOX 2)shcesses seewn cto os oceate mceees he eee eebedheweteece nesses | 5. 82 4.30 1.52

These well-dried seeds were then put up in seven different kinds of
packages:

(1) Double coin envelopes, of much the same quality as those in which
seeds are commonly sold.

(2) Bottles of 120 cc. capacity, closed with firm cork stoppers.

(8) Bottles of 120 cc. capacity, corked and sealed with paraffin.

(4) Tin cans having closely fitting lids, the whole being then care-
fully dipped in paraftin.

(5) Double coin envelopes, as for No. 1, the packets being then
dipped in melted paraftin.

(6) Double coin envelopes, the inner one paraftined, the outer envel-
ope being used simply to protect the paraflin and to facilitate ease of
handling.

(7) Double coin envelopes, with both the inner and the outer coated
with paraftin.

On February 15, 1901, one of each of the above preparations was sent
to Mobile, Ala., and stored in a cellar approximately 400 feet back
from the bay. After the lapse of 108 days, i. e., on June 3, these
samples were received in return, at which time germination tests were
made.

The other complete set, retained in the botanical laboratory at Ann
Arbor, was subjected to a very moist atmosphere. The samples were
kept in a damp chamber made by taking two battery jars of different
sizes, the smaller containing the seeds being placed within the larger,
which was lined with filter paper and then partially filled with water.
The whole was covered with a glass plate, and the atmosphere within
was always on the verge of saturation.

A third and an extreme set of conditions was established by keeping
some of the paraflined packages immersed in water for twenty-seven

EXPERIMENTS IN KEEPING AND SHIPPING. 67

days. At the end of that time (March 14) the seeds were tested for
germination, as were also those from the unprotected envelopes in
the moist chamber. The seeds that were kept under water in the
paraflined packages germinated readily and normally, showing no
deterioration in vitality; but the seeds from the packages not paraflined,
which were kept in the moist chamber, had been injured to an appre-
ciable extent, there being a marked retardation in the germination of
all of the species of seed. The cabbage at the end of thirty-six hours
had germinated only 11 per cent, as compared with 57.5 per cent for
seed from the immersed paraflined package. The relative merits of
the two conditions as affecting onion seed may be expressed by a
germination of 13.5 per cent and 39 per cent, respectively, after sixty-
one and one-half bours. Not only was 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 Table X XVI.

Germination tests were made of all of the other samples on June 3,
1901, the date when the seeds were returned from Mobile. Atthis time
the seeds in the unprotected envelopes in the moist chamber were so
badly molded that no germination tests were made. The samples from
Mobile, which were directly comparable with the above, except that
they had been stored in a basement, were greatly injured. The beans
had deteriorated to 88 per cent, the onion to 27 per cent, the pansy to
8 per cent, while the phlox was dead. However, seed of the other
species—cabbage, lettuce, and peas—gave final percentages of germi-
nation varying but little from the control, but the slowing down in
the rapidity of germination was sufficiently marked to show a corre-
sponding loss in vitality.

With the samples which were put up in bottles, tin cans, and
paraftined packages the results were quite different from those given
above. Inno 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 been stored in the moist chamber in the
laboratory. This sample of phlox germinated only 3.5 per cent.
Unfortunately, both the pansy and the phlox seeds used for these
experiments were not very satisfactory. These samples were at this
time nearly two years old and consequently of a low vitality. The
tabulated results of the foregoing experiment follow.

68 THE VITALITY AND GERMINATION OF SEEDS.

Tabnte NN VI.— Vitality of seeds preserved in different kinds of packages.
Dura- Percentage of germination.
se li eree any te) ToS er : A ' Cab. | Let- On- ane Pan-| . - |Aver-
ment, | Beans. bage.| tuce. | ions. | P&8S-| sy. | hloX.)"5 ses,
Days.
CONGLOLS sec ostee fase Soe nets eee | aes ees 94.0 | 90.2 | 89.5 | 97.5 | 90.0 | 37.7 4255 |. 77.34
Ann Arbor, Mich., moist chamber:
EDV ClOPGS aa scan swtcas cee neceseasseees 27 80.0 | 91.0 | 76.5 | 90.0 | 88.0 | 25.0 0.0 64.35
Bottlecorked ssc nc acs ao cee oe fees | 108 98.0 | 91.5 | 91.0 | 93.5 | 94.0 | 36.0 31.0 | 76.43
Bottle; parafiined. 22-2. osansccc a © | 108 97.5 | 93.5 | 90.5 | 95.5 | 90.0 | 39.5 | 39.0 | 77.93
Tin Can paraimined: = aa== sane asec 108 96.0 | 87.0 | 90.0 | 93.0 | 90.0 | 35.0 3.5 | 70.63
Two envelopes, outer paraflined .... 108 98307 | 91.5} 9155" 1)97.:0)-92305) 838250 )) Q7iZoele7ba6b
Two envelopes, inner paraffined .... 108 98.0 | 94.0 | 89.0 | 93.0 | 88.0 | 24.0 | 47.0 | 76.14
Two envelopes, both paraflined ..... 108 96.0 | 90.5 | 86.5 | 95.5 | 92.0 | 23.0] 38.5 | 74.57
Two envelopes, both paraffined and |
immersed in water.........--..... 27 | 100.0 | 88.5 | 88.5 | 94.5 | 90.0 | 34.5] 80.5 | 75.21
Mobile, Ala., basement:
IRUIVClOPES acces nkie a een cuwatiewiteseee ae 108 88.0 | 86.0 | 88.0 | 27.0 | 96.0 8.0 0.0 (56.14
Bottle Rr COTKedie. eae Sos eee 108 | 98.0 | 91.0 | 90.5 | 95.5 | 84.0 | 34.5 | 92.5 75.14
"SBOE, PALHiMCd..s.ceensecessceuee- 108 98.0 | 90.5 | 92.5 | 95.5 | 92.0 | 34.5 44.5 | 78.21
Tin can, paraffined...............25. 108 | 96.0 | 88.0 | 95.0 | 96.0] 88.0) 26.0] 23.0 | 73.14
Two envelopes, outer paraftined .... 108 94.0 | 90.5 | 89.0 | 95.5 | 92.0 | 29.5) 34.0 | 74.78
Two envelopes, inner paraftined .... 108 | 96.0 | 92.0 | 88.0 | 90.0 | 98.0 | 38.0] 38.0 | 76.43
Two envelopes, both paraffined ..... 108 100.0 | 92.0 | 89.5 | 88.5 | 90.0 | 2.5 Oo. | V4aed4

Subsequent experiments were made, using envelopes of different
qualities, as well as varying 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.

(4) Envelopes made of a medium quality of waterproof paper.

(7) Envelopes made of the same quality of parchment paper as for
the preceding series, but paraftined previous to being filled 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 with seed, sealed, and then
the entire package was dipped in paraffin at a temperature of from
Do- to,602..0,

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 different 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. Unfortunately,
no special precautions were taken to dry the seeds. They were simply
air-dried samples; hence they contained a quantity of moisture sufli-
ciently large to give rise to an increased relative humidity of the
confined air in the paraflined packages. This increased humidity was

EXPERIMENTS IN KEEPING AND SHIPPING. 69

accompanied by a greater activity within the cells, and consequently
by a greater deterioration of vital force. For this reason the results
are not as definite as the conditions warrant. Nevertheless, some
important facts were brought out by the experiments which justify
their being discussed and tabulated (in part) at this time.

Cabbage: Per cent. Per cent. | Per cent. Per cent. Per cent. Per cent.
Ann Arbor, Mich........ 91 90 86.5 90.5 | 85.5 86.5
Mobile, Ala........-.-.-- 30.5 57.5 | 85 || 38 50.5 5
Baton Rouge, La........ 70 63 2°65: | 73.5 79.5 35.5

Lettuce:

Ann Arbor, Mich........ 89.5 89.5 96.5 91.5 90 93
MODIe; “Alase22 2 sccicccue 80 75 64 78 78.5 61.5
Baton Rouge, La........ 81.5 77.5 74 82 78,5 72.5

Onion: |
Ann Arbor, Mich........ 91 90 93 91.5 89 89
MODE: Alas 2s 3.5 cc ass.ce 0 4 0 0 4.5 0
Baton Rouge, La........ 1 20 | 0 5 40 0

| |
AV OTARG Sic cads neeees 59. 39 62.94 | 49, 44 | 61.11 65. 66 49, 22
|

In the first place, the injury resulting from the effect of the climatic
influences is quite 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 by the marked difference in the two seasons. The summer of 1900
was extremely wet in the South, especially at Mobile, while the sum-
mer of 1901 was exceptionally dry. Concerning the conditions Zim-
mer Brothers wrote on November 26, 1901, as follows:

We do not think you will find much difference in the two packages. The season
this year has been 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 great 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 the relative value of
different packages as a means of putting up seeds.

In Table X XVII it will be observed 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; but the ¢om-
parisons to be made between the ordinary paper packets and the
paraftined packages are worthy of consideration. The envelopes that
were paraflined after being filled with seed 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 paraftined, 62.94 per cent for the envelopes dipped in
paraftin after being filled with seed, and 49.44 per cent for the seeds-
men’s envelopes. In dry rooms the results were 61.11, 65.66, and
49,22 per cent, respectively. These averages were somewhat higher
than the true conditions of Baton Rouge and Mobile warrant, as the
results of the germination tests from all of the packages retained at
Ann Arbor showed but little variation. Taking the three samples of
seed which were stored under trade conditions in Mobile, the average
percentage of germination was 24.2 for the seed from the nonparaftined
package and 45.5 percent for the seed from the paraflined package, show-
ing a loss in vitality of 77.3 and 49.5 per cent, respectively, considering
the germination of the Ann Arbor sample asastandard. At Baton Rouge
the results were slightly better; the average percentages of germination
were 32.2 for the seeds from the nonparaflined and 53.5 per cent for
the seeds from the paraflined packages, representing a loss in vitality
of 65 and 40.5 per cent, respectively. While in either case the loss
was very great, still the advantages of the paraflined packages are
worthy of consideration for the reason that a prolongation of life for
only a few weeks is frequently of the greatest importance, particularly
in districts where much fall planting is done.

In this connection may be given the results of some other tests,
which really were a part of this same experiment, but included only
onion seed. This seed was put up in seedsmen’s envelopes and in
paraflined envelopes like those previously described. In addition,
seed was also put up in small bottles, which were corked. ‘These
packages were kept ina small box within a suit case carried on two
trips across the Atlantic and on a tour through Central Europe, thus
subjecting them to very variable conditions. Germination tests
gave the following results: Seed from the ordinary packages, 77
cent; paraftined envelopes, 90 per cent; bottles, 91 per cent.

To test more thoroughly the keeping qualities of seeds in paraftined
packages and in bottles, another series of experiments was begun on
December 20, 1901. For these tests only cabbage and onion seeds

EXPERIMENTS IN KEEPING AND SHIPPING. fe

were used, but each with three different degrees of moisture: (1) Seed
from the original packages, i. e., air-dried samples, the cabbage hav-
ing a water content of 5.80 per cent, and the onion 6.48 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 2.41 per cent, thus raising the water con-
tent to 7.63 and 8.89 per cent, respectively. (8) Air-dried seeds
which were dried in an incubator for eight days ata temperature vary-
ing from 27° C. to 39° C. During this interval 2.05 per cent of water
was expelled from the cabbage and 3.11 per cent from the onion seed,
leaving a water content of only 3.75 per cent in the former and 3.37
per cent in the latter.

Each of the samples, treated as just described, was put up in three
different kinds of packages: (1) Seedsmen’s regular seed envelopes.
(2) Similar envelopes which were paraflined, after being filled with
seed, ata temperature of from 70° to 75°C. The melting point of the
paraftin 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
herbarium room of the botanical laboratory, in a greenhouse, and in
an incubator maintained at 40° C. The duration of this experiment
was 131 days, from December 20, 1901, to April 30,1902. The results
of the germination tests are given in Table XXVIII. Two percentages
have been given for the control sample, one for Ann Arbor and the
other for Mobile. This was necessary since the two series were tested
at different times and comparisons can not be made interchangeably
between the two.

TaBLE XX VITI.— Vitality of cabbage and onion seed as preserved in various kinds of
packages and subjected to different conditions of storage.

[Germination of control samples—Ann Arbor: Cabbage, 81.7 per cent; onion, 74 per cent. Mobile:

Cabbage, 88 per cent; onion, 84.5 per cent.]

Percentage of germination.

Percent- || Scare ees a ee

se ee Special treat- age of | Ann Arbor, Mich. Mobile, Ala.

Envelope......... NODC 22 225.152 5. 8Q 81.0 81.0 68. 0 72.5 60.0 10.0
10Yot Soret eons ETAT ce occe 5, 80 80. 0 79.0 85.5 62.0 87.5 52.5
IBOtIe Re sesee aeeee Corked) 223. .<< 5. 80 79.5 85.0 85.0 68.5 84.0 84.0
Envelope......... INOUGH s. csc cee fed |e ae ODs, 80.5 65.5 74.6 64.5 15.5
On. selrsne- aes Paratiness.55- 7.63 80.5 82.0 83.5 69.5 86.5 46.5
IBOULIG™ eka eee Corked --.....- 7.63 80.5 85. 0 86.5 48.0 82.0 91.5
Envelope....----- INQMC@%s. 2203 322 3.75 | 76.0 85.5 67.0 73.0 64.0 9.0
DOSS sone cee Paratiieeees.t: 3.75 | 86.0 84.0 76.0 71.0 82.5 78.0
Bottle: ssc. ssocecee Corked ....... Be 75iie S3a0 $4.0 74.0 64.5 82.5 85.0

12 THE VITALITY AND GERMINATION OF SEEDS.

Taste XN VIII.— Vitality of cabbage and onion seed as preserved in various kinds of

packages and subjected to different kinds of storage—Continued.
| Percentage of germinatien.
| _ =
5 P | ;
: Special treat- ear Ann Arbor, Mich. Mobile, Ala.
See And ment of water |_ ]
, a package. content | B0tan-| trade |. Incuba- | Trade .
of seed. nee condi- nee torat | condi- Base:
apdbo- . . 10use, Wal | « . | ment.
ratory. tions. 40° C. | tions. |
Onion: |
Envelopesés: --...2 None osenaee 6.48 7825) |ty ‘6985 SED 47.0 19E51|" LONO
T
DOS aSe 3 seins = oe Para tim 2j0- 6.48 76.5 66.5 67.0 4.5 83.0 27.0
Bottle as |\Gorked 2-2: 6.48| 73.5] 71.5] 60.0 64.0} 86.0] 825
Envelopess--2-- ==. Non@ 223.222. 8.89 74.5 60.0 11.5 28.0 21.0 2.5
Doe: Leake ss | Paraffin ...... 8.89 | 74.5] 66.0] 56.0 9.0 74.5 21.0
Bolen tf recescsee Corked:222.-2 8.89 78.0 68.0 67.5 3.0 HES} 78.5
Envelope.......... eNOneta eres So 6155 63.5 8.5 ? 6.0 17.0 | 6.0
DOpscaseaess see Parafin =....- 3.37 75.5 72.5 58.0 9.0 77.0 60.5
|
Bottlee-tso.cece=e Corked#222 5-2 3.37 76.5 41.0 77.0 59.5 84.5 | 81.5
; |

Many of the points brought out by this table are very similar to
those of the preceding one, yet the differences are sufliciently 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 germinated practically the same, the cabbage slightly
favoring trade conditions and the onion being better preserved in the
laboratory. Buta comparison of the trade conditions at Ann Arbor
and Mobile in the unprotected packages shows the same wide variation
that has been already pointed out.

The advantage of drying is not very clearly brought out in this
table; in many cases there seems to have been a slight injury as a
result of the high temperature at which the drying was done. Una-
voidably the temperature at that time reached 39° C., which, as has
already been stated, is slightly above the maximum to which seeds
can be subjected for any considerable time without injury. The
injury due to heat is very evident in the samples stored in the incu-
bator maintained at 40° C., this injury being more apparent with the
increased moisture, especially in the paraflined package and in the
bottle. However, on the whole the percentages of germination are
higher for the dried seed than for the seed which had absorbed an
additional quantity of moisture; and, indeed, the comparison should
properly be made with these two, for seeds as they are usually stored
contain even higher percentages of moisture than either the cabbage
or lettuce after they had absorbed the additional amount of water.

But the chief purpose of the present experiments was to determine
the relative advantages of envelopes, paraffined packages, and bottles
as methods of putting up seed in order that vitality might be pre-
served for a longer time. This comparison is best made by consider-

EXPERIMENTS IN KEEPING AND SHIPPING. 3
ing the vitality of the seed stored in the greenhouse at Ann Arbor and
under trade conditions at Mobile. It will be readily seen that the
vitality of the seed from the unprotected packages was greatly reduced,
while those from the paraftined envelopes and from the bottles germi-
nated nearly as well as the controls. These differences are better rep-
resented diagrammatically, as follows:

Diagram representing the percentages of germination of cabbage seed when treated as

described,
; Percent- |
Kind of Bpeciel wea eine Ann Arbor, Mich., green- Mobile, Ala., trade
package. package. moniter house. | conditions.
of seeds,

1D a) (0) oa ea ee eee 580 || a0 60

DOI aoc aniase Paraffined .... 5. 80 | 92.1 87.5
IBOuLLeet eae ae Corked ....... 5.80 | 91.5 Sd
TEV GLO DON ces 92 ees ese aanen = at 7.63 | 70.5 64.5

DOweee 2... Ss: Paraffined .... 7.63 | 89.9 | 86.5
Bottles sseeaesc.- Corked ....... 7.63 | 93.1 | 82
BV. ClO DG esnacee | acces caene aes 3. 75 | (ees | 64

DOR Ta acecc ex Paraffined .... 3.75 | 81.8 | 8215
BS GublGL esse cise - Corked ....... | 7a 7Oe7 82.5
Control sample .| Original pack- 5.80 | 88 | 88

age, |

Diagram representing the percentages of germination of onion seed when treated as described.

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 comparable with the results from the Mobile series,

74 THE VITALITY AND GERMINATION OF SEEDS.

all being based on the vitality of the controls, as shown by the tests
made at that time, the standard being 88 per cent for the cabbage and
84.5 per cent for the onion.

A discussion here hardly seems necessary, as there can be no doubt
that seeds retain their vitality much better in moist climates if pro-
tected from the action of the atmosphere. This may be accomplished
by dipping the packages in paraffin or by putting the seed in bottles.
Disregarding the expense, bottles surpass paraflined envelopes as a
means for the preservation of vitality, and also in the 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.

From a practical point of view it has been conclusively shown that
moisture is the controlling factor in seed life. Seeds stored in a
humid atmosphere soon lose their vitality, but if carefully dried and
protected from moisture life is greatly prolonged.

The question at once presents itself: In what way does the presence
of increased quantities 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 vesp/ration. Seeds as
we commonly know them absorb oxygen and give off carbon dioxid;
that is, respire.“ During their respiratory activities the energy
stored within the seed is readily evolved, the vital processes are
destroyed, and life becomes extinct. The intensity with which respi-
ration takes place is largely dependent upon the humidity of the sur-
rounding atmosphere, which ultimately resolves itself into the amount
of water in the seed. The respiratory activity is directly propor-
tional to the quantity of moisture absorbed by the seed up to a certain
point, attaining its maximum during the process of germination. — It
has been found that a decrease in the water content results in a cor-
responding diminution in the intensity of respiration and consequently
in a prolongation of the life of the seed as such.

Bonnier and Mangin’ were the first to show that respiration in liy-
ing plants increases with an increase in the humidity in the surround-
ing air. As this is true for growing plants, it is even more marked
in stored seeds. Maquenne’ suggested that a reduction in moisture
is accompanied by a reduction in respiration, but at that time no
experiments had been made to show that such was actually the case.

« Kolkwitz (Ber. d. deutsch. Bot. Ges., 19: 285-287, 1901) reports respiration in
recently ground seeds.

6 Ann. se. nat. bot., ser. 7, 2: 365-380, 1885.

¢ Ann. Agron., 26: 321-332, 1900.

RESPIRATION OF SEEDS. 5

In 1832, Aug. Pyr. De Candolle wrote in the second volume of his
Physiologie Végétale that the vitality of seeds would be prolonged if
they were buried sufliciently deep in the soil to protect them from
oxygen (or air) and moisture. Unfortunately, De Candolle did not
discover the true cause of this prolonged life, for nowhere did he
make any reference to respiration. Nevertheless his general conclu-
sions were properly drawn. De Candolle also stated that light acceler-
ates evaporation in seeds and thus causes a premature death. Here,
however, his results were wrongfully interpreted. These conclusions
are applicable only in case of seeds that die if allowed to become dry.
The real effect of light is to cause a slightly accelerated respiration
and consequently a greater deterioration in vitality. Jodin“ states
that light accelerates respiration to a marked degree. His experi-
ments were with peas which contained 10 to 12 per cent of moisture.
Two samples of peas were placed, each under a bell jar, over mer-
cury. One sample was kept in the light and the other in the dark.
At the end of 4 years 6 months and 14 days an analysis of the con-
fined air from the sample kept in the light gave the following results:

Peas, 3.452 grams, in air, in light: Per cent.
Oey Oth le aha etre sos ese ea Slk eset one Sess tes 19. 1
INiitraye’ crimes tees er ees 2 es es Se Sele ee etre Sn oes cee oe 78.6
(Gs RIL el Cleese eerie ae eae ed ne Ge yey Fa. ei ee ees 1.2

At the end of 4 years 7 months and 14 days an analysis of a sam-
ple of air taken from the other chamber was as follows:

Peas, 3.580 grams, in air; in dark: Per cent.
USS (fel es See 2 ee eee ene ee eee eee 20.8
Pig ene Re ASS Sok Sia ae Nh oh cigenaewac keen 35, SS ata Ths)!
Gar momo xd eeewe see ah fede LE eA Se. bee Baa SS ee = ad

The 3.452 grams of peas that were subjected to the influence of the
action of light had absorbed, in the given time, 2.4 cc. of oxygen and
produced 1.8 cc. of carbon dioxid. The seed kept in the dark showed
but 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 respt-
ration, still the above results do not furnish sufficient 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
‘ase 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 7.976 grams of peas, sealed, in air,

@ Ann. Agron., 23: 483-471, 1897.
+b Bul. Soe. bot. France, 29: 25-29, 1882.

76 THE VITALITY AND GERMINATION OF SEEDS.

in a tube, respired quite freely. After the lapse of two years an
analysis of the confined air gave the following results:

Per cent.
(0). 6\172(2) 1 Beene ere ee See eee le Ren ke se 8 hoe 14.44
Nitrogen! 6. 2542 2502 2 See ee a Se Oe ee ee ee ee 81. 74
Car bony dioxid i. <: ke 2 22 a os es es eee ee ee 3. 82

These same seeds germinated 45 per cent and had increased 745
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 870 days. The
concentration of the carbon dioxid in the flask at the time the gas was
drawn for analysis was 1.54 percent. This sample of seed germinated
97 per cent, and there was only a very slight retardation in germina-
tion, which indicated that the vitality 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 air drawn 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 be present, and that intensive respiration is accom-
panied by 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 chamber for 175 hours, so that an additional quantity
of moisture could be absorbed.

Control samples of air-dried seeds were also kept in sealed bottles
and subjected to the same subsequent treatment. After the lapse of
one year analyses of the confined gases and germination tests of the
seeds were made, the results of which are given with the general
details.

Beans.—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 ce. of carbon dioxid. The loss in weight was only
0.05 per cent, but the vitality had fallen from 100 to 86 per cent, as
shown by the control.

Cabbage.—Of cabbage seed, 10 grams, with an additional 9.79 per
cent of water, were used for this test. During the year this sample
of cabbage seed had given off 24 cc. of carbon dioxid, an equivalent of
2.4 ec. of carbon dioxid per gram of seed per year. The control
sample germinated 89 per cent, but this seed was dead,

=|
i>
OC
ate

RESPIRATION OF SEEDS. 77

Carrot.—Of carrot seed, 10 grams were allowed to absorb during
175 hours an additional 10.25 per cent of water. In one year 27 ce. of
‘arbon dioxid were produced, giving a concentration of carbon dioxid
of nearly 12 per cent. The deterioration in vitality was from 84 to 0
per cent, as compared with the control.

Lettuce.—Of air-dried lettuce seed, 10 grams were allowed to absorb
an additional 8.87 per cent of water. During the experiment 19.5 ce.
of carbon dioxid were formed, an equivalent of approximately LO per
cent of the original volume of the inclosed air. These seeds were all
killed. The control sample germinated 94 per cent.

Onion.—Oft air-dried onion seed, 10 grams were allowed to absorb
an additional 10.11 per cent of water. The seed gave off 26.5 ce. of
carbon dioxid during the experiment and deteriorated in vitality from
97 to 0 per cent.

A bottle containing 4 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 fromthe 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:

(a) Fifty grams of air-dried seed were sealed, in air, in a bottle of
500 ce. 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:

Per cent.
ORY AOE = ate = eg Se Seen eee ore oe eee ee eee ere 12.27
INCH RLECOYEC ST AY hes Ra ate ae tet a an eee 85. 87
Cane CI CPR eee Septet eee ee eee ee ake oe ed elt ee 1. 86

(>) Fifty grams of air-dried seed were sealed, in air, in a 500 ce.
bottle, with 4 cc. of water in a small test tube at the bottom of the
bottle. Nearly all of the water was absorbed by the seeds, there
being an increase in weight of 3.6475 grams, or 7.3 per cent. The

composition of the inclosed air was:

oe
ro]

Per cent.

OEY I Re en te ee ee None
DG en 8 2h Se erage ea Seems se Sisk Ss oh cin seme ha 86. 65
Carnhonadioxil wees sate Leesa lies see Roemete obec oo dec eb se tes wateees 13. 3:

The oxygen had all been consumed and the seeds were all dead.
(c) Fifty grams of onion seed were sealed in a 500 cc. bottle, in a

78 THE VITALITY AND GERMINATION OF SEEDS.

mixture of illuminating gas and air. The increase in weight was only
0.04 per cent. An analysis of the inclosed gas was as follows:

Per cent.

ORY PON £c8 o.50 222 eee Se eee 2 ee ee ee 3.23
Garbondioxids i242 -< 1 eee eee eee ae ae eee ee Th PAL
Methane and ‘nitnoven =! dc es ecco sso ee ee ae eee ee 95. 96

(7) Another 50-gram sample of onion seed, belonging to a different
series, was sealed in a bottle of 300 ce. capacity, and showed the
following composition of the inclosed air:

Per cent.
OR yen! 23042. poet a ee eee eee eee ee ee ee 8. 02
Nitrogen. «lic. e~ 24 erate ee i ee ea ee eee ea tela LY
Carbon:dioxid! =< 200 oe ee eB ee ene oe eee 6.81

In only one case was there any deterioration in vitality, namely,
where the large quantity 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 question yet to be solved. The protoplasts of the
individual cells gradually but surely become disorganized. C. De
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 says, 1s comparatively short,
for respiration soon ceases and life becomes wholly 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 suffer any degree of reduction in temperature
without being killed. The killing of the seeds experimented with
(lobelia) he attributes to the fact that the protoplasm had not become
inert, but simply subdued, and the seeds were thus affected by the low
temperature.

Asa result of later experiments C. De Candolle,? in keeping some
seeds under mercury to exclude air, concludes that ‘* seeds can continue
to subsist in a condition of complete vital inertia, from which 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.
b Pop. Sci. Monthly, 51: 106-111, 1897.

RESPIRATION OF SEEDS. 79

It is now quite generally accepted that respiration is not absolutely
necessary for the maintenance of seed life, notwithstanding the fact
that Gray contended that seeds would die of suffocation if air were
excluded.“ The experiments of Giglioli’ in keeping seeds of Jed/cago
sativa immersed in various liquids 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 prohibiting respiration.

Kochs¢ succeeded in keeping seeds for many months in the vacuum
of a Geissler tube without being able 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 seeds were not killed. However, his vitality tests can not be
considered as entirely satisfactory. In the first place, the number of
seeds used (ten) was 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 vacuum over sulphuric acid for 182 days. During this time all of
the free water had been extracted from the seed. When again con-
nected with a vacuum 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 cent as compared with 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 commonly know them, is
not interfered with if they are kept in conditions prohibiting respira-
tion. Brown and Escombe® hold that all chemical action ceases at
temperatures of liquid air. They accordingly conclude that ‘* any
considerable internal chemical changes in the protoplasts are rendered
impossible at temperatures of —180° to —190° C., and that we must
consequently regard the protoplasm in resting seeds as existing in an
absolutely inert state, devoid of any trace of metabolic activity and
yet 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.”

a Amer. Jour. of Sci., 3d series, 24: 297, 1882.
b> Nature, 52: 544, 1895.

¢ Biol. Centrbl., 10: 673-686, 1890.

@Proc. Roy. Soc., 54: 335-337, 1893.

éIbid., 62: 160-165, 1897-98.

sO THE VITALITY AND GERMINATION OF SEEDS.

Giglioli” arrived at practically the same conclusions when he said:

It is a common notion that life, or capacity for life, is always connected with con-
tinuous chemical and physical change * * * The very existence of living matter is
supposed to imply change. There is now reason for believing that living matter
may exist, in a completely passive state, without any chemical change whatever,
and may therefore maintain its special properties for an indefinite time, as is the
case with mineral and all lifeless matter. Chemical change in living matter means
active life, the wear and tear of which necessarily leads to death. Latent life, when
completely passive in a chemical sense, ought to be life without death.

But even though ordinary respiratory exchanges are not necessary
for the maintenance of vitality, and granting that intramolecular
respiration does not occur in the resting protoplasts, there is no exper-
imental evidence pointing to the fact that all chemical action ceases,
although some writers, as has already been shown, maintain the view
that living matter may exist in a completely passive state. If ‘*com-
pletely passive” meant devoid of respiratory activities none would dare
dissent; but that seeds are entirely quiescent under any known con-
ditions has not been proved. To conceive of all activity ceasing
within the seed under certain conditions, and that with such cessation
of activity an immortality of the seed is possible, 1. e., if such con-
ditions continue to exist, is, from our present knowledge of the chem-
istry and behavior of the living cell, impossible. In Giglioli’s experi-
ments respiration was undoubtedly prevented, and, according to his
own conclusions, vitality should have been preserved, for he says ‘*in
the absence of any chemical change the special properties may be main-
tained indefinitely.” But, in his own experiments, the special prop-
erties were not maintained, for all of the seeds with which he experi-
mented deteriorated yery much, and many died. Granting that those
which suffered the greatest loss in vitality were injured by the pres-
ence of the particular gas or liquid used there remain no means of
accounting for the deterioration in those giving the highest percentages
of germination. His experiments were made for the most part with
Medicago sativa, which, under ordinary conditions of storage, is espe-
cially long lived. Samek? has shown that seed of J/edicago sativa 11
years old was capable of germinating 54 per cent. Giglioli succeeded
in getting a germination of only 56.56 per cent after a little more than
16 years in hydrogen, and 84.20 per cent when they had been kept in
carbon monoxid. Jodin ¢ kept peas immersed in mercury for 45 years
and they germinated 80 per cent. After 10 years the vitality had
fallen to 44 per cent. Nobbe obtained a germination of 33 per cent
in peas 10 years old which had been stored under normal conditions. —
Likewise the experiments of Brown and Escombe do not justify the

“Nature, 52: 544-545, 1895.
> Tirol. landw. Blitter, 13: 161-162, 1894.
¢Ann. Agron., 23: 4383-471, 1897.

RESPIRATION OF SEEDs. 81

conclusions which they have drawn. It is now definitely known that
all chemical actions do not cease at the temperature of liquid air. Thus
it can not be granted that the protoplasm becomes inert as a result of
the reduction in temperature. Maquenne“ more nearly expressed the
true conditions applicable to low temperatures when he wrote that
with dessication, at low temperatures, seeds are transformed from a
condition of diminished activity-into a state of suspended life. But
there are still other factors to be considered. The vegetative functions
may cease, metabolic processes may be at a standstill, intramolecular
respiration need not exist, yet vitality is not, nor ever has been, pre-
served; sooner or later life becomes extinct. What does this signify?
The gradual process of devitalization means chemical change, and
chemical change means activity within the cells. We must not forget
the great complexity of the composition of the protoplasmic bodies
which go to make up a seed. The chemistry of the living cell js still
surrounded by many difficulties and is likewise filled with many sur-
prises, and before the question of the vitality 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 that all organic compounds are made up of a very
few clementary substances, but the numerous and obscure ways in
which they are put together furnish questions of the greatest per-
plexity. Substances having the same elements may differ widely as
to their properties. Moreover, 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 with 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 immortality of
seeds will vanish.

(1) Seeds, like other living organisms, respire when subjected to
normal conditions of storage.

(2) Respiration means a transformation of energy, and consequently
a premature death of the seed.

(3) Within certain limits respiration is directly proportional to the
amount of water present in the seeds and to the temperature at which
they are stored.

(4) By decreasing the water content of seeds respiration is reduced
and vitality greatly prolonged.

«Compt. Rend., 184: 1243-1246, 1902.
25087—No. 58—O04 6

82 THE VITALITY AND GERMINATION OF SEEDS.

(5) In most seeds the quantity of oxygen absorbed greatly exceeds
the quantity of carbon dioxid evolved.

(6) Respiration is nearly as active in the dark as in the light.

(7) Respiration apparently is not necessary 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.

During the past decade the so-called unorganized ferments have
taken an important place among the subjects of biological research.
Our knowledge of their wide distribution has increased many fold.
The part they play in both anabolism and catabolism has furnished us
many surprises, but with all of the work that has been done our knowl-
edge of these most complex compounds is very limited.

The part that enzymes play 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
‘an 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,” Griiss,’ and Hansteen¢ are cited by Brown
and Escombe” as holding the view that the amyliferous cells of the
endosperm of the grasses can digest their reserve materials independ-
ently 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 Lupinus, Phaseolus, and Ricinus. In 1890, Brown
and Morris‘ did not find such to be the case; but the results of Purie-
witsch, Griiss, and Hansteen led to a duplication of the experiments
by Brown and Escombe in 1898. At this time they demonstrated that
the amyliferous cells play no part in the chemical changes which take
place during the process of germination, but on the contrary that the
enzymic action in the endosperm of the grasses is confined to the
aleuron layer.

But the purpose of the present paper is not to consider the localiza-
tionof the particular enzyme, and much less the action of enzymes
during germination. At this time quite another question is to be

« Pringsheims Jahrb., 31: 1, 1897.

> Landw. Jahrbiicher, 1896, p. 385.

¢ Flora, 79: 419, 1894.

@Proc. Roy. Soc., 63: 3-25, 1898.

é Jour. Chem. Soc., London, 5'7: 458-528, 1890,

ENZYMES IN SEEDS. 83
considered, viz, In what way do enzymes function in the preservation
of vitality ?

Maquenne “ points to the view that the vitality of seeds is dependent
on the stability of the particular ferment present. He attributes the
prolongation of vitality in seeds that are kept dry to the better preser-
ration of the enzymes. This view has been largely strengthened as a
result of the investigations made by Thompson,’? Waugh,’ Sharpe,” and
others, in which they have shown that the artificial use of enzymes
may greatly increase the percentage of germination in some old seeds.
By the use of diastase the percentage of germination of 12-year-old
tomato seed has been increased more than 600 per cent.

If the suggestions made by Maquenne were true in every sense, then
dead seeds should be awakened into activity by artificially supplying
the necessary enzymes; but this can not be, or never has been, accom-
plished. True, many experiments have been recorded in which a
greater percentage of seed has been induced to germinate by the judi-
cious use of commercial enzymes than by the ordinary methods of
germination; but this treatment is applicable only where the vital
energy is simply at a low ebb and does not in any way affect dead
seeds. The experiments of the writer with naked radicles from the
embryos of living and dead beans have shown the presence of enzymes
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 embryos gave rise to
an energetic hydrolytic action. In all cases hydrolysis was sufficiently
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 begun, giving only
a brown color with iodin, but not reacting with Fehling’s solution.
Results of a similar character were obtained from portions of the seed

#Ann. Agron. 26: 321-332, 1900; Compt. Rend., 184: 1243-1246, 1902.

> Gartenflora, 45: 344, 1896.

¢ Ann. Report, Vt. Agr. Exp. Sta., 1896-97, and Science, N. 8.,.6: 950-952, 1897.

¢Thirteenth Annual Report, Mass. Hatch Exp. Sta., Jan., 1901, pp. 74-83.

e This was a sample of ‘‘ Valentine”? beans grown in 1897. The same year they
tested 97.3 per cent. In March, 1898, the same sample tested 87 per cent. At this
time they were sent to Orlando, Fla., where they remained until May 8, 1899,
approximately fourteen months. The beans were then returned and numerous
germination tests were made at irregular intervals, but in no case was there any indi-
cation of vitality. Several samples were also treated with ‘‘Taka’’ diastase (solu-
tions varying in strength from 2 to 10 per cent), but none was stimulated into
germination. The radicles were tested for enzymes in the spring of 1902, nearly
three years after the beans first failed to germinate, at which time they were nearly
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 the living
and dead beans each giving clear reactions with Fehling’s solution.
A third series of tests was made by stopping the germination of beans
when the radicles were from 1 to 1.5 em. long. These were then kept
quite dry for nearly seven months, after which the dessicated radicles
were broken off and macerated like the above. This solution was then
allowed to act on starch paste, and the transformations were 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 the disorganization of the enzymes present. There is some-
thing more fundamental and probably more complex to which we must
look for this life-giving principle. True, as Maquenne has suggested,
there is a close relationship between the loss of vitality in seeds and
the decomposition of enzymes.

In order to determine what such a relationship might signify, the
following series of experiments were made:

Beans, peas, cabbage, lettuce, onion, phlox, and pansy seed, with
definite quantities of good commercial ** Taka” diastase, were put up
in bottles of 120 ce. capacity, as follows:

(1) In bottle closed with cork stopper.

(2) In bottle closed with cork stopper and paraftned.

(3) 0.5 ce. of water in the bottle with the seeds and the diastase, the
bottle sealed with paraftin.

(4) 1 ce. of water in the bottle with the seeds and the diastase, the
bottle sealed with paraffin.

(5) 2 ce. of water in the bottle with the seeds and the diastase, the
bottle sealed with paraffin.

(6) 3 ce. of water in the bottle with the seeds and the diastase, the
bottle sealed with paraftin.

(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 filter
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 quantity of the dry powdered diastase,
were then maintained at the temperature of the laboratory fora period
of 85 days. 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 SEEDS.

Taste XXIX.—Loss in vitality of seeds with varying degrees of moisture when kept at

ordinary room temperature.

[Duration of experiment, 85 days. ]

aThe samples prepared, excepting the control, were in bottles of 120 cc. capacity.

The above table shows that there was a gradual deterioration in
vitality as the quantity of water was increased. All stages of injury
were manifested, but it is not necessary to enter into a discussion of
the table at this time, inasmuch as similar tabulations, showing the
injurious effects of varying quantities of moisure on the seeds, have
already been 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 45° 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 sufticient to
‘~ause a complete hydrolysis of the 10 cc. of 1 per cent starch solution.
In Nos. 1547, 1548, and 1549 the samples from the control bottle, the
paraftined bottle, and the paraftined 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 bottles 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 water in the bottle and 5 ce. of the diastase solution were
required to hydrolyze the 10 cc. of the 1 per cent starch paste. No.
1553—the sample from the bottle which contained the 4 cc. of water—
showed that the diastase had been almost completely 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, purplish-blue color. In this
last case the average percentage of germination had decreased to 37.6
per cent, as compared with 76.6 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 vitality 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 any way
governed by the particular enzymes present. In fact, the evidence at
hand better substantiates 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 much 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 more 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 by the use of ether.

In the third place enzymes can not be the chief factors controlling
the vitality of a seed, because the more sensitive growing point of
the radicle suffers injury much in advance of the other portions of
the seed. Not infrequently in making germination tests do we find
that the growing tip of the embryo is dead, while other portions of
the seed may still be living and capable of carrying on all normal met-
abolic processes. The bean is one of the best examples for demon-
strating this fact. Here the radicle may be entirely dead, yet the
cotyledons may still be able to make some growth; but in all seeds
where the growing tip is dead the remaining portion of the radicle
may be living, in which case adventitious roots may be formed and
growth may continue for a considerable time, though very rarely will
a healthy seedling be developed. It thus seems quite clear that the real
vital elements are 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
undoubtedly necessary for the normal development of a seedling, but
the points above given show that the life of a seed is not entirely

a Bot. Gaz., 1899, 27: 458-466.

SUMMARY. 87

dependent on the stability of the particular ferment or ferments
present. There is something more remote, possibly of a simpler but
probably of a more complex composition, to which we must attribute
the awakening of the metabolic processes. Reference is not made
here to the zymogenic substances which develop into the particular
ferment, for what has been said of the latter applies equally well to
the former. If the zymogens were perfectly preserved the resulting
ferments would be developed normally and germination would continue
in the usual manner.

In conclusion, it may well be emphasized that no single element or
compound can be isolated as the sole source of vitality in seeds.
There must be a combination of factors, each of which plays an
important role in the preservation of vitality. The destruction of
any one of these factors may upset the principles governing 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 vitality, for unless it continues to function no other
growth can take place. Other parts of the cell, however, may be of
equal importance. At all events all hope of future gain must come
from more critical studies of the cell contents to know their chemical
composition and possible reactions. A correct solution of these perplex-
ing questions is nothing less than a determination of the fundamental
principles of life. What will be the ultimate results no ene is prepared
to say.

SUMMARY.

(1) A seed isa living organism, and must be dealt with as such if
good results are expected when put under favorable conditions for
germination.

(2) The first factors 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 they soon lose their vitality. On the other hand,
well-matured seeds, harvested under favorable conditions, are com-
paratively long lived when properly handled.

(4) Seed harvested in damp, rainy weather is much weaker in vital-
ity than seed harvested under more favorable 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 beer
thoroughly matured and properly harvested and cured, is largely
dependent on environment.

88 THE VITALITY AND GERMINATION OF SEEDS.

(7) The average life of seeds, as of plants, varies greatly with differ-
ent families, genera, or species, but there is no relation between the
longevity of plants and the viable 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 greatly prolonged beyond that which we know
at present, though never for centuries, as is frequently stated. Cases
so reported can not be taken as evidence of the longevity of seeds.

(9) It is known that seeds retain their vitality much better in some
sections of the country than in others. The part which climatic influ-
ences play in the vitality of seeds is of much more importance than is
generally supposed.

(10) Experiments have shown that mo7sture is the chief factor in
determining the longevity of seeds as they are commercially handled.
Seeds stored in dry climates retain their vitality much better than
when stored in places having a humid atmosphere.

(11) The deleterious action of moisture is greatly augmented if the
temperature be increased. Not infrequently is vitality destroyed
within a few weeks or months when the 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 always be dry. If seeds could be kept dry and at the same
time cool, the conditions would be 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 vitality 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 best 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 be 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 first 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 40° C. (102.2° to 104° F.)

SUMMARY. 89

will cause premature death. If the seeds are kept in a moist atmos-
phere a temperature of even 30° C, (86° F.) will soon cause a marked
injury.

(17) Seeds can endure any degree of drying without injury; that is,
by drying in a vacuum over sulphuric acid. It is believed that sueh
a reduction in the water content is necessary if vitality is to be pre-
served for a long period of years. However, with such treatment the
seed coats become very firm, and there usually follows a retardation
in germination as a result of the inability of the seeds to absorb water
rapidly enough to bring about the necessary physical and chemical
transformations for the earlier stages of @ermination.

(18) Seeds that are to be sent to countries having moist climates
should be put up in air-tight packages. Experiments have shown
that by the judicious use of bottles and paraftined packages seeds can
be preserved practically as well in one climate as in another.

(19) It is of the utmost importance that the seeds be dry before
being sealed in bottles or paraflined packages. A drying of ten days
at a temperature of from 30° to 85° C. (86° to 95° F.) will usually be
sufficient. However, a better method to follow is to dry until no
more moisture is given off ata temperature equivalent to the maxi-
mum of the region in which the seeds are to be distributed. If this
is not done, the subsequent increase in temperature will liberate an
additional quantity of moisture, which being confined in the package
will leave the seeds ina humid atmosphere and a rapid deterioration
in vitality will follow.

(20) Experiments in storing seeds in open and sealed bottles and in
packages with definite quantities 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 temperature.

(21) Of a series of experiments the average loss in vitality of seeds
kept in envelopes in a ‘dry room” was 21.19 per cent, ‘‘ trade condi-
tions” 36.63 per cent, ‘* basement” 42.28 per cent, while the loss in
the case of seeds stored in bottles was only 8.08, 3.92, and 4.51 per
cent, respectively. (See Table X XV.)

(22) Seeds under ordinary conditions of storage respire quite freely,
and respiration is much more rapid if much 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 necessary to the life of seeds, as they can be
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 the vitality of a seed after res-
piration has ceased indicates a chemical activity within the cells, giving
rise to a transformation 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 activity, 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 many factors,
but the one important factor governing the longevity of good seed is
Aryness.

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Just, L. Ueber die Wirkung hoherer Temperaturen auf die Keimfiihigkeit der
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Ueber die Einwirkung héherer Meriper raturen auf die Gaetiunecdter Keim-
fiihigkeit der Samen. Cohn’s Beitriige zur Biol. der Pflanzen, 2: 311-348, 1877.

Kocus, W. Kann die Kontinuitiit der Lebensvorgiinge zeitweilig vollig unterbrochen
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Kotxwitz, R. Ueber die Athmung ruhenden Samen. Ber.d.deut.bot. Ges., 19:
285-287, 1901.

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1899.

Recherches sur la germination. Ann. agron., 26: 321-3382, 1900.
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92 THE VITALITY AND GERMINATION OF SEEDS.

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aN Oe a

Page.

Agriculture, Department, Seed Laboratory, relation to present work ...------ 10
Wlabama, Auburn: seed-storing experiment .s.<.. -........-.-2s255<5-s2-2- 49
Mla cends sc eculomMor Experiment 2-222 — a. asia ac ieeaie tet eae sees ee 10
Amyliferous cells, relation to germination of seeds, note.--.-.----------------- 82
Angina ciurulius. selection fOr CX periment. a5 se 2252-3 - 3-2 sees 10
Amn Arbors, Mach. -seed=storime experiment -_--2.. 2.52. =< --2 32 554-2. 50
TeshiMovEXpenlmeniie a6 sees - a eece nse eee 14-22

Apiacex, Daucus carota, selection for experiment --.......------+-----+--+=- 10
Apparatus for tests of effect of moisture on vitality of seed .......----------- 30) oil
SECO estino= CEserl PuOnaNd US 2-8 Sais cre nee Sassen ee oe 11-12

. Asteracex, Lactuca sativa, 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
SEOdestOnin ov ex MeNUNMeNb mse Sale soe 5 lo None asics ciws oa 49

LestIN Ne PEMIMCN (Sees eee Goto Me 22 sie St ote re S 14-22

Sanh ee omicemOlse SLOraee, UCC... 2-62 5- eon den secu wes secdesceese scone 28
Sel PCH OMG ROX OERIN CMG 2 eos ae ces ne ean cig w smug ew aioe SSE 10
Beans, germination tests, results for various storage conditions ...-------- 51, 63-65
Bec eres mination experiment, Tesulis: 22.2. s2es.s-- Sele oot os ceees- 76

Al emulne@nmnlOstsies as 4" ee aseee casera hak ees atielec Rm tlan esse 83
Bluegrass, Kentucky, Poa pratensis, heating in curing, effect on seed... -~----- 43
Bonnier and Mangin, plant respiration, conclusion ......--.---------------- 74
Van Tieghem, tests of respiration of seeds, results .....-.------- 75

Brassicacex, Brassica oleracea and Raphanus sativus, selection for experiment. - 10
Brown and Escombe, seed germination experiment.......------------------ 80
views as to chemical action at liquid-air temperature - - - 79

Brown and Morris, and Escombe, experiments as to enzymes in germination - 82
Cabbage, germination tests, results for various storage conditions - .------- 53, 63-65
seed, comparison of storage in three climates......---.------------ 21-22
TCCaHOUSCISLOLAC eM CHOCL sam ctse Emenee oa ese See si 28

moisture and temperature tests of vitality ............------- 36

MesprdiOn ex perinent, TesUltss. 22... 225 2.024 he. ceases 76

vitality in different packages in varying storage .....--------- 71-74

BelcCHOn Tam Cx perme Nt a6 fa 0 2S Soca ewts dg 2 madame ssa wheelie 2 10

Carbon dioxid, result of respiration of beans, etc .......--..-.----------- 76, 77, 78
Carrot seed, germination tests, results for various storage conditions - ~~ .-- 55, 63-65
Fespiration 6x periments, TESults 2 22a ona ccc wecwes eae eee s-s 77

BeleUiot Tones perin el ts sete ek slot Soltis ota cles ante <= ~10 == See See 10
Cauliflower seeds, keeping in moist climate, note .......----.--------------- 13
(harcoal,.moss, etc; shipping seed.in packing... -..- 2.22.2. ~ss<2--4 s+ 47
Chemical activity, relation to latent life...........:....-..---+-4.---5------ 80
Glement. succeshon tor storage of seed: .-- 52.5... = 22-5. ++ 2s se eee nse +: 45
Climates, different, causes of loss of vitality in seeds, discussion ...-.-------- 22-24
Climatic conditions, effect on vitality of seeds, discussion .....-.------------ 138-22
Corn, sweet, germination tests, results for various storage conditions... 56-57, 638-65
SeleciWOm 1OPGmperiguenl eons. -29e- 1-62. -nien n~ 32 wees so ters s 10

Coville, Frederick V., preface on purpose and scope of present study .--.---- 5
Cucurbitacex, Anguria citrullus, selection for experiment .......------------- 10
Curing and drying of seeds, necessity for thoroughness.-...-....------------ 45
Pmsecd MEN pOT NCOs ee! aac acne raat econ icie = ah ieee oS Sere 87

De Candolle, Aug. Pyr., remarks on conservation of seeds...-..-------------- 44
suggestion regarding vitality of seeds ........------- 75

Grawie We ont respiration: Ob SCO0S 26 as on eee 2c cece Sse 78

Diastase; use in experiments on vitality of seeds......-..------------------- 85
Dry atmosphere in open bottles, effect on vitality of seeds ...--------------- 34
sealed bottles, effect on vitality of seed ......-.---------- ot
heabecteetonrvitality Of Seed, NOlS 22. cont camo ~ 23. eal seen - 31
Drying and curing of seeds, necessity of thoroughness. --.--.----- ae ee 45

94 INDEX.

Page.
Dryness, most important 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 invpreserying vitality. 2202 4- 2- a4 ee 82-87
Escombe and Brown, experiments as to enzymes in germination ....-.------ 82
seed-germination experiment.2.: 740-02 +-< a eee 80
views as to chemical action at liquid-air temperature. - - 79
Fubacex, Pisum sativum and Phaseolus vulgaris, selection for experiment. - - ~~ - 10
Fazy-Pasteur, suggestion toristorace, ofiseed 2s sss-— 55s ee eee 45
Ferments, relation tocvitalitysot seedsso 5-2 22 sans ee ee 90
unorganized, relation to vitality of seeds............-.-..-------- 82-87
Ferry Botanical Fellowship, seed study, relation to present work ......-.---- 10
Ferry,, D. Me) (ci Co.“seedtfoniexpen ments 2 eon ee ee eee ee 10, 15
Flor ida, Lake City; seed-storing-experiment! 2.225522 52a eee ees 49
testing-expernment*® 253. soo chee a ee 14-22
Gardener; market, value ot'eood'seedee = 2-4 45-.22 o ee eeseee soe eee 46-47
Gardeners;complaints*ohseéds; motes se. sas. 2s ae eee eee 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 es pe Bah PAP SESSA SS oaS cH e 26-27
in ice: house; effect:of package. 222-22 ce eee e see 27, 28
various seeds, percentage under differing storage. ........---- 63-65
partof enzymes. 2:32.22 Se ae ae eee ee ee eres 82
tests'and apparatus, discussion - 9-222 252s eee == ee ere 11-13
TeSUlts fs 2/254 cose Seas Sess Rates ie ee ee 50-65
Germinator; seed testing, method of use 2222-22 2422545 sce ee eee eee eee 12
Giglioli, conclusion as to chemical activity in latent life.......-.-..----.---- 80
experiments with seed of Medicago sativa.......---.---------.------ 79
remarks on vitalityofseeds 22 522.) a ae et hee ee ee eee 45
Grasses, endosperm, relation to germination=...-- =-22-- Ss. 2 soo ce ee 82
Gray, contention as to suffocation of seeds... o222.2 23: sso see eee = eae 8,
Griiss, citation ag to: prassiendosperm..2. 22) 20) 2.2 te ee eee See eee 82
Gulf of Mexico, effect of moisture.on seeds...--2 52. -2 S25 s5ce 4 seco eee 13
Hansteen, citation as to‘erass endosperm: — 23)25- S26. see ae ere 82
Harvesting, relation to vitality of seeds -......--.------- cae asia bitte i tee ee 87
Heating, excessive, danger in curing seed! i222 1. 2 es eet eee 87
Hygroscope, crude, improvisation from awns in! seed: testing: <2. 24> se eee 3
Hydrolysis, presence in experiments on enzymes in seeds, notes. . ----- 83, 84, 85, 86
Tee, packing of seeds, effect on vitality, TEMATKSs, 6 25,282 ee ee oe eee 26-29
cco seed, test for effect of moisture on v ltalityoes 2 Sie eee eee 48)
Indian Territor y, Wagoner, place for seed-testing @xperiments:).5.-- eee 14-22
seed-storing experiments = 22. S222] 3-2 =e 50
Jodin, seed-germination experiment, note. -...-..-.---------------------- iar 80
statement as:to respiration Ol Seeds 2. 4° = 2s neoe eae ee ce ne See eee 75
Keeping seeds, discussion: (see also Storage)... 2.---- = 22-22 \ae5- oe eee 65-74
Kochs, seed-respiration experiment.¢ => 2022527 eae eine ee a re 9
Lactuca sativa, selectionsoriexperiment:- 522-5222 .5oeee 22 nee ee eae 10
Latent life, relationtolhchemicalactivity 2222s. -- = — 2c =e ee 80
Lettuce, comparison of storage in three climates. ...-.-.-.-.-----------+---:- 21-22
germination tests, results for various storage conditions. ....--.-.-- 58, 63-65
seed, ice-house storages ieilect a. == ee eee ease res eae ee 28
loss'of vitality im tropical climatesnote2= 2. 222 see. eee 25
moisture and temperature test ofavitality ss 24 see = eeeeen 36
respirationexperiment, results. —=2. 225-2522 eee 77
selection for'experiments<'-52..20 se. so. ae eee ee ee 10
Tiliacez, Allium cepa, selection for experiment. ---2--252=2--=-s>--2-22-- = 10
Longe vity of seed, dry Ness; Mostampontant tacto Ges mee ae eeeee 90
Lycopersicon lycope rsicum, selection for experiment. .......-.--.--.-.--<----- 10
Maquenne, statement as to seeds in low temperatures, note. .--.-.-.-----------. 81
suggestion as to respiration of seeds -..2---------326--—--4- eee 74

suggestions as to vitality of seed8__.------2--2. --2e22s-- + sen aoee 83

INDEX. 95

Page
Market cardener, value of good seed, remarks--.-.-------..----------------- 46-47
MaITLEy erelauiOn LO vitality OMECCUS, Se oe ete S-. tees ciests awe it oelote5. +t 87
Mangin and Bonnier, plant respiration, conclusion. ....-.-------------------- 74
Medicago Savinas Seed experiments Ol GislOliss 222 22 a J foal ten eee nce 79
Giglioli ANG SaMekK =. aco. = 5 saan 80
Michigan, Ann Arbor, seed-storing SNPCMMMCMsies 2B ato eee en eee 50
University, seed study, relation to present work .......-.--------- 10
Mobile, Ala., comparison with Baton Rouge and Ann Arbor for storing seed.. 21-22
place tor seed-testing experiments... 222 s2..c<225ssseesces5 14-22
seed-storing experiment pF EEA 0 EOS, IS NR eee eee ere ye eer 49
Moist atmosphere in sealed bottles, severe injury to seeds ......-.-.--+.----- ata)
~ Moisture and temper ature, effect upon vitality of seeds, discussion .....-.---. - 24-36
summary of results - 35
relation to vitality of seed, tables and comment... - _ 38-44
effect on vitality of seeds at high temperatures, remarks....-------- 29
in fixed temperatures, discussion .....---- 36-44
hindrance in keeping seeds, provision.....-----.------------------ 18
relationsto,endurance ol heat by seed). ----.--2....---s22-ss--2---5 25
MOND OVILY GMeehs..582 4.2 Se ooo ee ccs} dale on 87, 88, 89, 90
LesuOMccedsum special packaves! 2222.2 225.85. e ee hace e enn 66
Morris and Brown, experiments as to enzymes in germination.......-------- 82
Nites ecnacecodl: CLC. SHIPPile SCCU 222. - So eee aeons eee Se aot on ee seen 47
New Hampshire, Durham, place for seed-testing experiments -.......------- 14-22
seed-storing experiment.-----..----------------- 50
New Orleans, rapidity of deterioration of seed..-....---..------------------ 47
Newcombe, Dr. F. C., direction of present study ...--....---.-------------- 10
Nobbe, seed germination experiment, note...--...----.-------------------- 80
Oily seed, resistance of low temperatures, note ....-.-.-....----------------- 28
Onion, germination tests, results for various storage conditions .....-.---- 59, 68-65
seed, comparison of storage in three climates......--.----..---------- 21-22
1CesMOUSeIStOLASC: ClOGh i.e amet ot Pee ses ce Auk ose os See 28
moisture and temperature test of vitality -.......-------------- 36
Fes WiranwOm ex Panliments- TESMMtSms asthe Asse aoe e eS fa cies 77-78
vitality in different packages in varying storage .....----.------ 71-74
SCLECHLOM PF OME XO CHINN CTI oi, e eae Sts aed ce came el- oes cleni Se here tars 10
Packages, seed, different kinds for moisture test ......-...------------------ 66
relation to preservation of vitality of seeds.........--.------ 89
special, experiments in shipping and keeping seeds ....----------- 65-74
Packinoyseed or shipping Cx periments +. ..-,02<.2---e<<-2 5. ane eee ceecie a 47
Pansy, germination tests, results for various storage conditions -.....----- 60, 638-65
SEC ETD Sat Wey. O\ela 00 (210 es ee ee 10

Paraffined packages, vitality of seeds in storage.....------------------------ 69-7
Rear sc lechloniOmexpenmen te. 5555 aise) Soe oe eset e ee ne ose see oe 3 10
Peas, germination at temperature of ice water, remarks ......--.----------. : 27
tests, results for various storage conditions.....-.------ 52, 63-65
seed, moisture and temperature, test of vitality .-.-.---..-------..--.- 36
Phaseolus vulgar FSASCLECUOM LOT Sb Wiiers Se ate Ne oe en gee lie aide Sonica a 10
Phlox, germination tests, results for various storage conditions ...-.-.----- 60, 63-65
isimsdivulie Selection 100 CXPeTUMENts .c.. <a sonn ews ease ene te ee swe eens 10
iplanitarse complaints OL SCGGs) NOL. = 35.5 cto oweces ada tee --~ = sere c ones wees 1M:
Poa pratensis, beating in.curime, effect ion seed. 2... -.:..-+-------+--------- 43
Poacex, Zea mays, selection for experiment, note ........------------------- 10
Poison, danger from brass and copper in seed testing, notes. ...--.-.--------- LES
Polemoniacexr, Phlox drummondii, selection for study ....-..----------------- 10
Porto Rico, San Juan, seed storing experiment ..........--.---------------- 48
LOSE OLE XMENIMCMIGMe ee! Oo oe ott S ose eee 14—22
Precipitation and temperature, relation to vitality of seeds, percentages .---.- 23
effect on vitality of seeds, graphic representation eee ee 24
Protoplasm, changes in respiration Ge Seem eee Oy sete So tse's See So 78
Protoplasts, changes im respiration experiments... 202... 2.2.5.2. 2-2-2 ee! 79
Puriewitsch, citation as to PTAss CNCOsPCMMi ee: aust... ete gsece Hest eSs 82
Radish, germination tests, results for various storage conditions. ....-.---- D4, 63-65
SSlechiGmmrom ex POniMel cee een eees oh cea eens e's 10
Respiration, necessity to.lifée of seeds; remarks: +... l.-.+. .-2.-2-s--+22-+--8 79

Ol Seeds" GISCUSSION ee aclecee een cec Sa EEO SEU EES WEE Ra | 74-82

6 INDEX.
Page
Respiration of seeds, summary of conclusions. -..--.------------------------ 81-82
relation to-vitality of seeds’: -_ .-..2.- “se! 22 62s tee 89, 90
Romanes, seed respiration experiment .......------------------------------ 79
Samek, seed germination experiment, note. ...---------------------+----#-- 80
Sharpe, citation as to enzymes. .-----.------------- eos Bea ee is eee 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, ete., remarks ..----2-22-22- 2222 — eee 47
Soaking seeds for germination tests, advantage..--.--..-- eto Soe 12
Solanacex, Lycopersicon lycopersicum, selection for experiment... ...----------- 10
Spalding, Prof. V. M., direction of present study ---..---------------------- 10
Starch in seed, relation to germination in ice-house storage... ----- Le ee 28
Storage (keeping) and shipping of seeds in special packages, discussion. - ----- 65-74
room, warehouse, character for seeds, remarks.........-------+----= 46
seed, relation to preservation of vitality... .-.-- = ai $2 88, 89
Storing and shipping seeds, methods for preservation of vitality.....---.----- 44-65
seeds, relative merits of Mobile, Baton Rouge, and Ann Arbor.....-- 21-22
Temperature and moisture, effect on vitality of seed, discussion...-.-..------ 24-36
summary of results --.-- 30
relation to vitality of seed, tables and comment... 38-44
precipitation, relation to vitality of seed, percentages. ---.-- 23
maximum limit of endurance by seed, variation.......--.-.---- 25
relation to vitality Of secedss2- 5. +2 see ceeee eee eee 87, 88, 89-90
Temperatures, fixed, effect of definite moisture on vitality of seed, discussion. . 36-44
high, vitality of seeds, effect of moisture ......-.-..-.-------- 29
Test, germination, first, for climate, results, table and comment --.----- 15-16, 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, cermination, results._-<_o 2. 2. <2 Se ceca eee ee oe 50-65
various veretable- seeds... 3.2 225... 525--- 2. 5 eee iat
seed, for effect of moisture on vitality at high temperatures .......--.-- 29
vitality, importance of nearness to planting time.......--.---- 47
Thompson, citation as to enzymes:__.... .- <2 Se ee ee oe 83
Tomato, germination tests, results for various storage conditions... ----.-- 61, 63-65
seed, 1ce-house storage, effect 2..2. 322.22 522-252) sk eee 28
moisture and temperature test of vitality -....-...------------ 36
selection for eéxperiment.2--22---sccn-e-2 see eo: - 10
Tropical climate, loss of vitality of lettuce seed .....-.....-s.-ssadeese eee ees 25
Vacuum, seed respiration experiments............------------------------- 79
Van Tieghem and Bonnier, tests of respiration of seeds, results ......-------- 75
Violacex, Viola tricolor, selection for experiment.........--.----------------- 10

Vitality and germination of seeds, conclusions from present study, summary.. 87-90

vabbage and onion seed, relation to storage and package ......--..-- 71-74

seed, effect of climatic conditions, discussion ...............--.-.--- 13-22

definite moisture in fixed temperatures, discussion .... 36-44

temperature and moisture, discussion...........-.---- 24-56

enzymes IN. Preservation 22.26... oc. 26 2c2 be ee eee eee 82-87

loss for various seeds under different storage conditions ....._.- 63-65

indifferent climates, causes's.-2-.2 32.0252... 25-2 eee 22-24

with varying moisture at ordinary temperature ..........-- 85

low, worse than déad seed, note..2. - 2.22224: 2... 46

preservation by methods of storing and shipping ..........---- 44-65

relation of moisture and temperature, tables and comment --.- - 38-44

storage in different kinds of packages, results......-....-.----- 68

Warehouse, seed, storage, character, remarks .........--.-----<------------ 46
Water content of seeds, increase, effect on vitality _.........-...---.-2------ 44
Watermelon, gemination tests, results for various storage conditions -_.-. - 62, 63-65
seed; ice-house storage, effect....../. Lee msces sc. sae eee 28

selection for experiment ...... 5.2522 2.<5s.-eee ee eee 10

Waugh, citation as to enzymes -. suc 2. ..2- 22.5 soe ee ele eee eee 83
Zea mays, selection for.experiment, note J2cs-1.2...- 22. aaseeeeeee ee eee 10

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