6s 8 



MAIZE 



CHAP. 

 XIII. 



612. The Tip Cap. — The tip cap is a small cap which covers 

 the tip end of the grain and protects the end of the embryo. 

 It is composed of material somewhat resembling that of the cob, 

 and comprises from \\ to 1 1 per cent of the whole grain. It con- 

 sists mainly of carbohydrates (S7 per cent). When the grain 

 is very dry and hard, the tip cap sometimes remains attached 

 to the cob in shelling ; failure of the seed to germinate has 

 been attributed to the consequent exposure of the radicle of 

 the embryo. 



The chemical composition of the tip cap is as follows : — 



Table C. 

 PERCENTAGE COMPOSITION OF THE TIP CAP. 



613. The Hull. — The hull, husk, or skin, is the thin outer 

 covering of the grain, corresponding to the pericarp of a fruit. 

 It comprises from 5.1, to 6 per cent of the whole grain. 



Table CI. 

 PERCENTAGE COMPOSITION OF THE HULL. 



