VARIATION IN COMPOSITION 275 



the proportion or percentage of protein becomes 

 smaller as the plant becomes older. The impelling 

 purpose of the plant is to produce seed. Whenever 

 the water supply begins to give out, or the season 

 shortens in any other way, the plant immediately 

 begins to ripen. Now, the essential effect of dry- 

 farm conditions is to shorten the season; the com- 

 paratively young plants, 5^et rich in protein, begin to 

 produce seed; and at harvest, seed, and leaves, and 

 stalks are rich in the flesh- and blood-forming element 

 of plants. In more humid countries jjlants delay 

 the time of seed production and thus enable the plants 

 to store up more carbon and thus reduce the percent 

 of protein. The sh(jrt growing season, induced by 

 the shortness of water, is undoubtedly the main reason 

 for the higher protein content and consequently 

 higher nutritive value of all dry-farm cnjps. 



Nutritive value of dry-farm hay, strain, and flour 



All the parts of dry-farm crops are highly nutri- 

 tious. This needs to be more clearly understood by 

 the dry-farmers. Dry-farm hay, for instance, be- 

 cause of its high protein content, ma)^ be fed with 

 crops not so rich in this element, thereby making 

 a larger profit for the farmer. Dry-farm straw often 

 has the feeding value of good hay, as has been dem- 

 onstrated by analyses and by feeding tests con- 

 ducted in times of hay scarcity. Especially is the 



