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TEXTBOOK OF BOTANY 



those of the bean, the pea, and their relatives, contain large 

 proportions of protein food. In the wheat kernel-, as in that 

 of the corn, proteins are stored chiefly in the form of little 

 rounded bodies in the cells of the outer layer of the endosperm. 

 This layer is mostly or entirely removed in making white 

 flour, which thus contains much starch and only a very small 

 proportion of proteins. The outer layer of the endosperm is 

 kept, however, in the making of " whole wheat " flour, which 

 therefore contains a larger proportion of proteins than white 

 flour does. 



295. Distribution of Seeds. — We have seen that the fruits 

 of many plants are scattered in various ways. But in the case 



of other plants 

 whose fruit coats 

 split open, either 

 while the fruits 

 are still attached 

 to the plant that 

 bore them or 

 soon after their 

 separation from 

 the plant, it is 

 the seeds alone 

 that must be 

 scattered so far 

 as they are to be 

 scattered at all. 

 Such seeds are 

 distributed by 

 means much like 

 those that bring about the distribution of fruits. Many seeds 

 are extremely small and light and may be carried by the wind 

 to great distances. The blo\ving about of seeds is sometimes 

 helped by the presence of wing-like outgrowths of the seed 

 coat, such as those of the catalpa seed, or of tufts of hair like 



Fig. 171. — A seed pod of the milkweed and 

 escaping seeds. After Stevens. 



