GERMINATION AND GROWTH 37 
of wheat, oats, or barley before they are ready for harvesting. Try as 
many kinds as you like, and see how many will come up. Notice whether 
there is any difference in the health and vigor of plants raised from seeds 
in different stages of maturity. 
EXPERIMENT 33. THE RELATIVE VALUE OF PERFECT AND INFERIOR 
SEED. — From a number of seeds of the same species select half a dozen of 
the largest, heaviest, 
and most perfect, and 
an equal number of 
small, inferior ones. If 
a pair of scales is at 
hand, the different sets 
should be weighed and 
a record kept for com- ( nt ) 
parison with the seed- 
lings at the end of the 
experiment. Plant the Q HINGG 0g 4 (\ J) h\ 
two sets in pots con- 50 
taining exactly the Fias. 50, 51. — Stem development of seedlings: 50, 
same kind of soil, and aised from healthy grains of barley; weight, 39.5 
is rf ea a il grams (about 500 ers.) ; 51, raised under exactly similar 
cep. ‘on er i entica, conditions from the same number of inferior grains; 
conditions as to light, weight, 23 grams (about 350 grs.). 
temperature, and 
moisture. Keep the 
seedlings under obser- 
vation for two or three 
weeks, making daily 
notes and occasional 
drawings of the height 
and size of the stems, 
and the number of 
leaves produced by 
each. 
33. Resistance oS = 
to heat and cold.— Fias. 52, 53.— Improvement of corn by selection: 
Tn making experi- 52, original type; 53, improved type developed from it. 
ments with regard to temperature, notice how the extremes 
tolerated are influenced, first, by the length of time the 
seeds are exposed ; second, by the amount of water contained 
in them; and third, by the nature of the seed coats. Every 
farmer knows that the effect of freezing is much more in- 
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