PERIODS OF GROWTH. 83 
The relative length of each of these periods of growth 
in oats and sorghum (Chinese) is about as follows: 
Ist period. From germination until before 47 SORAREM: 
SHOOPIMNE: Jessacoseodedueseee seness 49 days. 60 days. 
eis, £8 From shooting of the stem until 
itis full grown (in flower).... 12 ‘ ao; §6 
aa. * PLOW CMD che ostosnasned\sedaeson one ens i Taps 
aon Formation of the seed.............. cia ee lo + 
bth = * PU POHUAO sa ccacucs ianscek vaseenssacioese fg tas 
OU AL acess tataansl daraan aa Gay ante Padi 
A careful study of the phenomena of growth manifested 
by these plants at different stages of their existence will 
reveal the fact that they bear a definite relation to condi- 
tions of climate prevalent only during regularly recurring 
periods in the progress of the seasons. 
Throughout the whole range of organic life, to plants as 
well as to animals, nature has imparted certain modes of ex- 
istence and peculiarities of structure adapted to the physical 
influences in contact with which they were designed to live. 
These essential differences must in all cases be provided 
for by the planter. ‘That method of culture, therefore, will 
be most nearly a true one by which these natural require- 
ments of the plant are the most fully satisfied. 
