282 



THE CEREALS IN AMERICA 



within the latter. The organs of reproduction are quite similar 

 to those in wheat. (56) 



380. The Grain. — The oat kernel, except in hull-less varieties, 

 remains enclosed in the flowering glume and palea. These 

 parts are usually referred to as the oat hull, but 

 are entirely different from the hull of maize 

 (228) or the bran of wheat. (64) In this book 

 the caryopsis of the oat will be called the kernel, 

 and the kernel plus the hull will be called the 

 grain. In general form and structure the oat 

 kernel is similar to the grain of wheat, but is 

 rather more elongated, while the pericarp is 

 characterized by its hairy surface. Richardson 

 found in an average of 166 varieties that 100 

 grains weighed 2.5 grams, with variations from 

 ^•75 ^^ 3-75 gi'aii^s per hundred grains.^ 



381 . Relation of Hull to Kernel.— The quality 

 of oats depends principally upon the proportion 

 of hull to kernel. The per cent of hull depends 

 both upon the variety and upon the conditions 

 of growth, varying from at least twenty to forty- 

 Am_erican varieties contain on an 

 average about thirty per cent of hull and seventy 

 per cent of kernel. It has been demonstrated 

 that there is no necessary relation between 

 weight per bushel or shape of grain and the per 

 cent of kernel or food value. The Illinois Sta- 

 tion, working during five years with from thirty to sixty varieties, 

 the seed of which was from various sources, but the crops all 

 grown under like conditions, found that generally varieties with 

 long, slender, comparatively light grains had the largest per cent 

 of kernel.^ The Ohio Station, working with seventy varieties 



1 U. S. Dept. of Agr., Div. of Chem, Bui. g. 



2 111. Bi'ls. 7, 12, 19 and 23, 



Magnified section of 

 portion of oat ker- 

 nel : p, pericarp ; 

 i, testa ; a, double 

 row of aleurone fivC per Cent, 

 ceils ; Sy endo- 

 sperm with com- 

 pound stare ii 

 grains. Nucellus 

 not shown in this 

 section. (After 

 Pammei.) 



