WHEAT. ' 107 



In the genus Triticum, to which wheat belongs, 

 there is but one spikelet at each joint and it is placed 

 flatwise, usually on a single spike. ^ We have in this 

 country some wild species which are usuaUy placed in 

 this genus. They are perennial. Wheat is not only 

 annual but the experiments of Lawes and Gilbert in- 

 dicate that artificial cultivation is essential to its 

 growth. Sir John Lawes is wont to say that if man 

 should disappear from the earth wheat would follow 

 him in three years. 



The process of milling consists in separating that 

 portion of the wheat berry which is desirable for 

 bread- making from the undesirable portion, and re- 

 ducing it to an impalpable powder. 



The wheat berry is covered by a light, colorless, 

 spongy envelope composed of cellulose, which is the 

 principal ingredient in wood and straw. The en- 

 velope is about three per cent, of the entire berry and 

 is almost, if not quite, indigestible. Botanically it is 

 not a part of the seed proper, but is equivalent to the 

 pod of the bean or the shell of the hickory nut. 



Within this envelope is the testa, or true cover- 

 ing of the seed, which is finer but similar in structure, 

 except instead of being colorless its cells are filled 

 with two coloring matters, one a pale yellow and the 

 other an orange yellow. These pigments give to the 

 berry its color, which varies according to the relative 

 abundance of the two. The testa is about two per 

 cent, of the berry. It is the portion which gives 

 millers so much trouble, as a surprisingly small 

 amount makes the flour dark and the bread darker. 

 The two envelopes described constitute the bran and 

 together make about five per cent, of the wheat. Th© . 



