—— 
‘ ‘ 
THE SEED AND ITS GERMINATION °9 
germination, we find that the principal ones are heat, 
moisture, and presence of air. A few simple experiments 
will show what influence these conditions exert. 
‘8. Temperature. — Common observation shows that a 
moderate amount of warmth is necessary for the sprout- 
ing of seeds. Every farmer or gardener knows that 
during a cold spring many seeds, if planted, will rot in 
the ground. But a somewhat exact experiment is neces- 
sary to show what is the best temperature for seeds to 
_ grow in, and whether variations in the temperature make 
more difference in the quickness with which they begin 
to germinate or in the total per cent which finally succeed. 
‘EXPERIMENT I 
"Relation of Temperature to Germination. — Prepare at least four 
teacups or tumblers, each with wet soft paper packed in the bottom 
to a depth of nearly an inch. Have a tightly fitting cover over each. 
Put in each vessel the same number of soaked peas. Stand the ves- 
sels with their contents in places where they will be exposed to dif- 
ferent, but fairly constant, temperatures, and observe the several 
temperatures carefully with a thermometer. Take pains to keep the 
tumblers in the warm places from drying out, so that their contents 
will not be less moist than that of the others. The following series 
is merely suggested, — other values may be found more convenient. 
Note the rate of germination in each place and record in tabular 
form as follows: 
No. of seeds sprouted in 24 hrs. 48 hrs. 72 hrs. 96 hrs. ete. 
At 329, eee i eee 
At 50°, —$> Ss —_—- Ss -——_--S ss ——_-_— —— 
At 70°, — —_ 9s —_--— —s ——-_—- —— 
At 90°,} —S ———_— Os ——.  ——-S 
“1 For the exact regulation of the temperatures a thermostat (see Handbook) 
is desirable. If one is available, a maximum temperature of 100° or over 
_ should be tried. 
