76 THE FEEDING OF ANIMALS 



that they are probably acted on more promptly by 

 ferments in the digestive fluids. 



The proportion of starch in plant substances varies 

 greatly. The dry matter of many seeds, such as rice and 

 the cereal grains, wheat, maize, barley, or oats, is largely 

 made up of starch. The same is true of potatoes and 

 other tubers. Johnson quotes the following figures from 

 Dragendorff :* 



TABLE XXII. AMOUNT OF STARCH IN DRY MATTER 



Per cent Per cent 



Wheat kernel .... 68.5 Peas 39.2 



Rye kernel 67. Beans 39.6 



Oat kernel ...... 52.9 Flaxseed 28.4 



Barley kernel . ^ . . 65. Potato tubers . . . 62.5 



It appears that in grain plants starch forms most 

 abundantly during the later development of the seed. At 

 the Maine Station none could be found in very imma- 

 ture field corn cut August 15, while on September 21 

 the dry matter of the whole plant on which the kernels 

 had matured to the hardening stage contained 15.4 per 

 cent. In general, the stem and leaves of forage plants are 

 poor in starch. 



The distribution of starch in seeds is worthy of note. 

 The grain of wheat has been carefully studied in this 

 particular, and it is found that this body does not nor- 

 mally exist in the seed coatings, this tissue consisting 

 largely of mineral matters, proteins, cellulose, and gums. 

 On the contrary, the germ and interior material deposited 

 around it are rich in starch. To be sure, wheat bran, 

 which is now very largely the outer seed coats of the 

 grain, has more or less, but this is due to imperfect milling. 



Starch is an important commercial article, and is 



*"How Crops Grow," page 52. 



