31 



a lens at the epidermis is sufficient for the identification of this 

 seed. Another striking characteristic of the cockle is the oval, 

 elongated starch aggregates found in the endosperm. These 

 starch bodies are made up of very minute grains. In size the 

 aggregates vary from 20 — 100^1 in length. (Winton.) 



COW HERB. 



{Vaccaria parviflora, Moench.) 



This seed is very rarely found in feeds in this country, but is 

 reported to be of common occurrence in Europe. The seed is spher- 

 ical in shape with a diameter of from 1.5 — 2 m.m.; has a dull 

 bluish black color and under the hand lens is seen to be free from 

 papillae on the surface of the epidermal cells. 



9 



9 



¥^ a 



Fig. 23. 

 hilum. 



Figure 23 

 Cow Herb, (o) Epidermal cells and rectangular cells from near 



The microscopic appearance of the epidermal cells in surface 

 view is characteristic of this seed, they being very regular in out- 

 line and saw-toothed, but are smaller than those of Saponaria 

 officinalis. The layer of thick walled rectangular cells found 

 near the hilum is also characteristic. The walls of these cells 

 are usually colorless, but the cell content itself is brown in color. 

 They resemble somewhat the pigment cells of linseed but are 

 smaller and not so purely rectangular. (Fig. 23.) 



