39 



CURLED DOCK. 



(Ruinex crispiis, L.) 



The seed of the curled dock is slightly larger than that of 

 the sorrel, having a length of from 1.5 — 2 m.m. The color is a 



7 O 



Figure 34 

 Fig. 34. Curled Dock. 



beautiful glossy reddish brown to brown; in shape the seed re- 

 sembles that of buclavheat but is proportionately broader at the 

 base. 



It is usually found whole in feeds. The seed coats are very 

 difficult to clear sufficiently to see the cell structure, but in well 

 cleared specimens the surface layer is found to be made up of 

 irregular cells with sinuous walls which are well defined and near- 

 ly clear. The cells are much larger than those of the sorrel. 

 (Fig. 34.) 



CHARLOCK. 



{Brassica arvensis, L.) 



This seed is very abundant, and is found in quantity in wheat 

 screenings, as well as an impiuity in other cattle feeds. It is a 

 deep brown to dull black in color and nearh' spherical in shape, 

 and the surface is almost smooth, showing practically no rough- 

 ness, even under the hand lens. In size the seed varies from 

 1 — 1.5 m.m. in diameter, being smaller than rape. 



The epidermal layer and the single layer of palisade cells, 

 containing a dark brown substance are the chief aids to a correct 

 diagnosis. 



The epidermal cells average COai in diameter and contain a 

 mucilaginous deposit, which when the cross section is mounted 



