12- 



ly broad even to the apex of the hair in rye, while in wheat it 

 becomes merely a line as it approaches the apex. 



The cross cells are arranged side by side in rows and are 100 

 — 200ac long, and 15 — Sdjj, wide. The side walls of these cells 

 are thinner than those of wheat, and the end walls are often 

 swollen, with intercellular spaces; in wheat the end walls are 

 thinner than those of the sides and there are no intercellular 

 spaces. 



The starch grains are also of aid in the diagnosis of rye prod- 

 ucts, they being of two distinct sizes, the larger averaging about 

 50/x but often exceeding this size, of a circular disk shape and 

 showing rings (laminae) and fissures radiating from the hilirni. 

 The small grains are round or angular and are from 8 — 14/^ in 

 diameter and are more numerous than the small grains of other 

 similar starches. 



Fig. 5 shows the different elements of rye which are useful in 

 the diagnosis of this grain when found in mixtures. 



BARLEY. 



{Hordeum sativum, L.) 



Barley or some of its by-products are of common occurrence in 

 cattle feeds, and as there is some similarity between it and the 

 other grains, as wheat and rye, it is sometimes rather difficult 

 to diagnose unless the whole kernel, coarsely ground, is present, 

 although some of the characteristics differ from others of this 

 group. The grain itself is shaped much like that of wheat, but 

 the glumes adhere more finiily to the seed and there are found 

 five prominent ribs which are not noticeable on other grains of 

 this character. The lateral depression is also more marked in 

 barley than in other grains. 



The epidermal cells of the glumes are strongly silicious in 

 character. There are three forms found; first, long cells with 

 thick wavy side walls; second, elliptical or circular cells which 

 have the appearance of short hairs and also circiilar or elHptical 

 cells which are usually found in pairs. These elements are shown 

 in Fig. 6. 



The parench}-ma cells of barley are rectangular in shape, with 

 thin walls, and large, roughly circular intercellular spaces which 

 are more or less characteristic of this grain. 



