Nitrogen -free Extract Starches 77 



It is somewhat customary to refer in a popular way 

 to the nitrogen -free extract of feeding stuffs as synony- 

 mous with starch and sugar. Such a comparison con- 

 veys an erroneous impression. The nitrogen -free 

 extracts of many feeding stuffs, notably the straws 

 and hays, contain at best, a very small proportion of 

 these carbohydrates, the amount of starch often being 

 inappreciable. It is doubtful whether these coarse 

 fodders usually contain enough to be chemically de- 

 termined. This has certainly been found to be true 

 in some cases. On the other hand, 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. John- 

 son quotes the following figures from Dragendorff: 



Amount of starch in plants 



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 im- 

 mature field corn cut August 15, while on September 

 21 the dry matter of the whole plant on which the ker- 

 nels had matured to the hardening stage contained 

 15.4 per cent. In general, the stem and leaves of for- 

 age plants are poor in starch. 



The distribution of starch in seeds is worthy of 

 note. The grain of wheat has been carefully studied 



