SEEDAGE 



jeoted; also it' 1 prr itui or nu.i-.- df vcvvd sclmIs l,r 

 fouml. 



The reference eulleetiun uf seeds should be kept in 

 neatly labeled f,'lass bottles, without neeks, ti^litly 

 stoppered and systeluatieally arranged in shallow paste- 

 board boxes (see Fig. 2:295). A eouveuient size tor (liese 

 bottles is -2 in. long by 3-5 in. iu diameter. A tTa\- 

 holding 100 of sueh bottles should fit into an (.rdiiiary 

 herbariuui ease, if the collection is large, a card index 

 will be of great assistance in Jiuding the specimens. 



Genniuati.ii, r.sts.-The seed.s used iu gerndualion 

 tests uuist be taken indiserimiiuuelv from" pure snd 

 which has been thoroughly mixed "for that purpose. 

 The selection .d' plump, uicedooking seeds for tins,- 

 tests, as frequently practiced, impair.s the autlienticU v 

 of the result. 



Tests may be conducted in the laboratory between 

 damp cloths or Idolters, or iu poroirs saurers.or in stind 

 or soil iu ;i greenhouse. .Seeds which are known to ger- 

 minate with ditliculty should be tested iu a greenhouse 

 as well as in the labortitory. The same is trite of any 

 species of seed whose conditions of gcrtnintitioti ;ire Dot 

 well Ulidcfstooil. 



While diitiip blotters serve as the best sulistratum 

 under ordinary circumstances, and especially where a 

 large nutnber of tests are to be made, thev do ntit 

 answer tis well for fine, sloW;germinating seeds like 

 tobacco and .Tune grass, and many flower-seeds, owitig 

 to the tacttltat the blotters sometimes adhere too dosclv 

 to permit the pro|ier circulation of air. Tliis mav In- 

 remedied to a certain extent byplacin- titirrow striji^ .d' 

 glass between the folds, but m'tiin relitmce iti such ctises 

 sliouUl be pdaced upon soil tests. 



All tests are to be made in cbiplicate. nsin- two lots 

 of 100 seeds each of petis, beans, corn, ciietirliits timl 

 others of a similar si/o. and LlilO seeds of clovir, i'tili- 

 bage, lettuce, etc. Tlie more seeds taken for test the 

 less the chance of error. However, 5 per cent to bi |ii.r 

 cent of variation may be expected between the two lots 

 of seed, even though they might have been ttikoti frotii 

 the same plant. In the case of a greater varittt ion thtin 

 10 per Cent the test should be repeated. .s,eds uiaju 

 which moulds form qnicklv are likelv to be (ild stocl<. 



The seeds should be inspected dtiilv. ti tiotr heittg 

 made of those having sprouted, which are tlien tlirown 

 out. In testing seeds of the pe;t f:im- 

 ily (Legumiuoste) one-thiiMl of tliosc- 

 remaining hard and fresh ;it tlie cb.)se 

 (:tf the test are usually cotintiMl tis h;tv- 

 iug sprouted. The average of the 

 duplicate tests is to be taken as the 

 percentage of vitality. Averages 

 should not be made, however, between 

 restilts obtained by different methods, 

 stich as blotters and soil. 



Laboratory tests are preferaldy nuole 

 oetween damp blotters p>l:tceii in a 

 metal chamber heated by gas, the heat 

 lieing controlled l:>y athermo-regulator. 

 The blotters must be free from solultle 

 chemicals. Blue blotters will be foitnd 

 less trying to the eye than white. Tlie 

 germinating chamber may be of titty 

 fortn which alkiws proper control id' 

 the ctnditions of light, heat, air titid 

 moisture. The standttrd chamber 

 ttdopted l.iy the associtttioti of .Vttteri- 

 can Agrictiltural Colleges and Experi- 

 ment Statious was designed by the 

 writer, ttntl serves equally well fiir 

 btLctericdogical purposes or ex]"fi- 

 ments iti ]'lant phvsicdog\' ;is for seed 

 testing (see Fig. 2296). 

 It is made of 20-ounce corrugated copper, and is 2 feet 

 long, 18 inches deep, atid 2 feet high, outside nietistite- 

 ments. The outside, except tire bottom, is covered with 

 two layers of felt, each H inch thick. 



A water spttce is tttfiu-ded by the double walls, ^vbi(d^ 

 extend cot ttll sides except the front and are 2 in. apttrt. 

 Entrance to this wttfcu' .jacket is obtained at 't, *f (Eig. 

 2296), while the water can be drawn off at r/. At c, c. on 

 the top, and at f, near the bottom of one enti, are 1-ittcli 

 openings into the citamber. One of the upper openings 



SEEDAGE 



1643 



^:^^ 



2295. 

 Bottle similar to 

 that used in 

 U. S. Dept. 

 Agric. for small 

 seeds. 



may be used for t!ie iiLs^Ttioii (,f a tljcrnjonieter. if d.-- 

 sn\-i\. Chviny:, lio\vevf.M-. lu ihr iiilhi.-nn:' wbirli tiip i-x- 

 t.<--Tual artiM.si.li.-rr exrrt.s ii|m,ii tIi.thk. nutters wlmsc 

 tiihrs aiv iiarth exii.is,.,!. iimvjsiuu |,;l^ been made tor 

 liuIdiiiL;- iwu tliennmiirlci's in a. Iiurizdital position, one 

 on the inside oJ: each ]ianci nf tlie door to the chamber, 

 by ineaiis of hooks of stout roppn- wire (Fig;. 2297, a, a). 

 The door is made in 2 iiaiids, each consisting of 2 

 phites of thick ghiss set about, '^ iu. apart iu a copiicr 

 frame, which is covered inside wilh felt. The inside 

 uuirgin of the dom U provi.jed with a projection (Fig. 

 22!I7, c) which tits snugly into a feh.dined 'groove (Fig. 

 22l>7, b), extending around the front side of the cham- 

 ber. The door is 3 in. shorter than the front of the 

 chamber, the remaining space being closed with copper 

 and provided with aventilator (Fiir. 2200, h), which per- 



2296. Standard seed-germinating chamber (front view, v^;th 

 one door slide removed'. 



Used by the United State:^ Department of Agriculture 

 and Amerit-au Experiment Stations, a. a, openings 

 into water jacket ; b, thernio-re^nlator: c, c. openings 

 into chamber; rf, gas enlr;nire tniie ; <', mii-robunsen 

 burner; /, gas exit : </, w;if.r < xit ; h. ventilator; i, j, 

 door slides: /.-. pan to hoM |n>]-in]s s;(U'-ers, etc. ; I, blot- 

 ter test; lit, porous saucers with sauj test. 



mits the exit of carbon dioxid, and cau be closed tightly 

 with a slide. Perfect closing of the <loor is further ef- 

 fected by a copper slide extending along the front mar- 

 gin, which catches firndy at the top and bottom of the 

 chamber (Fig. 2297, d, </}. This device, together with 

 the groove and its corres]iondinu- projection, are adapted 

 from the. Rohrbeck bactcrii>!o,!j;ical cliamber. The out- 

 siile door is furnished with a frame into which slide 

 two plates of galvanized iron painted dead black inside 

 and covered with felt (Fig. 229(i, i, j). By this arrange- 

 ment the interior of the chamber may be kept dark or 

 exposed to light, or, if de>irr<l, one-half may be dark 

 and the rest liij:ht. the otin-r eonditious remaining the 

 same. By raisiusj: these sliih-s the thermometers can be 

 read witln:)ut 'iipeuimj; the dour. Glass ])lates of various 

 e.)|ors mav be sulistitnteil for the slides, if the effects 

 of diftereut ravs of lii^dit 

 studied. 



Seven movable sJielves, ]il;ii- 

 in place by copper ledges ^4 in 

 are made of brass roibs 1'.. iu 

 capable of boldiuir uji (10 iionn^l 

 ture is controlled bv a low-temp 

 (Fig. 2290, b). A very low and 



plant-growth are 



be 



■d 2''4 in, apart, are held 

 i-b wide. These shelves 

 apart, and each one is 

 s wei-ht. The tempera- 

 u-ature tliernu>-regulator 

 ■(puibli- Ihune is secured 

 with a microbunseti burner ( FIl:-. 22',)0, c). One of the 

 o)ieniugs int(;» the water jacK"or ( Piu;. 2290, 0.) is 2 in. in 

 diameter to admit a K'Uix Ihcrmu-regulator, if a very 



