MICROSCOPICAL K\A.M I NATION. 77 



are found near the inner portion of the pericarp, and for the most 

 are rectangular in outline and usually from three to six times 



long as they are wide. 



In the wheat these cells have pronounced pits, giving the cells a 

 strongly beaded appearance. (Plate 1, lig. :>.) The pits occur promi- 

 nently at intervals around the ends of the cells. Intercellular spaces 

 are rarely seen between the ends of adjoining cells. The alcuron 

 iyer, showing the protein granules, is pictured in Plate I, fig. 4. 



In the rye the cells do not have as strongly pitted walls and the 



ids of the cells usually appear entire, being without pits and some- 

 what thickened. (Plate I, fig. 2.) Intercellular spaces are common, 

 due to the more rounded shape of the ends of adjacent cells. 



COTTONSEED. 



Four features of the cottonseed deserve attention. The first three 

 of these are found in the seed coverings. The outer layer of the -seed 

 coat consists of very irregular but usually somewhat elongated cells, 

 which are very characteristic of cottonseed. (Plate II, fig. 1.) They 

 are of light to rather deep brown color. 



The second coat, occasionally found, is the layer of palisade cells. 

 (Plate II, fig. 2). In the surface view they have an irregular honey- 

 combed appearance, and commonly crossing each cell are to be found 

 a few lines more or less parallel. 



The third layer of note is the delicate . membrane (perisperm) 

 enwrapping the embryo, and this looks like a network, with some- 

 what indefinite outlines. (Plate II, fig. 3.) 



If none of the foregoing structures was present it might be difficult 

 to identify cottonsee_d meal, though in the embryo there occur 

 numerous small rosette crystals of calcium oxalate, which are strongly 

 indicative of cottonseed. They will be found embedded in fragments 

 of the embryo, which, after clearing, have a bright light-yellow color 

 and which, with the small crystals, are not likely to be confused with 

 other structures that may be present in this class of cattle foods. 



LINSEED (FLAX). 



There are two structures of the linseed that are characteristic. 

 The first of these is a layer composed of long sclerenchymatous cells of 

 straw color. The pits in the walls give them a faint beaded appear- 

 ance. (Plate II, fig. 5.) 



The second layer of importance, from a diagnostic point of view, 

 are the quadratic pigment cells. (Plate II, fig. 6.) These cells are 

 commonly nearly square or polygonal, with nearly clear walls, but 

 containing brown-colored contents. In the walls are numerous fine 

 pits. 



