RELATION TO OLIMATE. 31 
2d. Those, like most of the annual grasses, which exhibit 
during certain periods no such equality of growth in the 
different parts. Instead of adding uniformly to every part 
of their structure the organized matter as fast as it is 
formed, they are busy at certain periods of their existence 
in accumulating it in special parts, from whence it is dis- 
tributed with great rapidity at particular periods to other 
parts toward which the vital energies of the plant seem 
suddenly to be diverted. In this respect, such plants bear 
a strong analogy to biennials, which, during the first year 
of their growth, accumulate in their roots the materials 
from which the luxuriant growth of the second season is 
rapidly evolved. Of this class sorghum is a conspicu- 
ous representative, as are also, to a certain degree, all 
our cereal plants. 
The relation which this peculiar mode of development 
bears to the climate of the different parts of the year is 
one of those beautiful examples of adaptation which meet 
the eye of the observer in every part of the kingdom of 
nature, and a proper knowledge of it is of primary import- 
ance in all our attempts to mark out a suitable plan of cul- 
tivation. Ahrend’s experiments with the oat-plant, and 
those of Anderson with the turnip, exhibit the strong anal- 
ogy which an annual of the class last described, in the early 
period of its growth, bears to a biennial plant, during the 
first year of its existence.* In both, before the close of a 
certain period after germination, the leaves of the young 
plant ‘‘lose the power of applying to their further growth 
the food which they had absorbed, and which now, trans- 
formed into organizable matter, was deposited in the roots. 
The same nutritive particles which went to form leaves, 
* Liebig, Nat. Laws of Husbandry. 
