WHEAT 107 



made up of three layers, which are separated only with 

 difficulty ; taken together they are called the bran. In 

 the milling of wheat, for the making of flour, the bran is 

 removed and used as stock feed, and does not enter into 

 the making of flour. The bran makes up about 5 per cent 

 of the entire kernel. Surrounding the kernel, immediately 

 under the bran, is a single layer of large cells called the 

 aleurone layer, comprising 3 to 4 per cent of the kernel. 

 In the milling of wheat this aleurone layer is not included 

 in the flour. Under the aleurone layer lies the endosperm, 

 which is made up of thin walled starch cells. The en- 

 dosperm makes by far the largest part of the kernel, 

 from 82 to 85 per cent, most of which enters into the 

 making of flour. At the base of the kernel at the side 

 opposite the crease will be found the small embryo or 

 germ. The germ of the wheat kernel is small in propor- 

 tion to the size of the kernel, when compared with that of 

 corn. 



TYPES OF WHEAT 



90. Classification. - The cultivated species of the genus 

 Triticum may be grouped into eight distinct classes or 

 types. According to almost all botanists, only three of 

 the types are considered as distinct species, the others 

 being sub-species. The following outline, arranged by 

 Hunt, shows the relationship of the eight types of wheat : 



monococcum (1) einkorn 



f spelta (2) spelt 



| dicoccum (3) emmer 



[ vulgare (4) common wheat 

 , I compactum (5) club wheat 



s | turgidum (6) poulard wheat 



[durum (7) durum wheat 

 polonicum Polish wheat 



Triticum 



stativium 



i 



