MEALS, BRANS, ETC. 



145 



The highly silicified glumes of the chaflf of rice have no feed vahie whatever 

 but rather interfere with the digestibility of other feeding material. Rice glumes 

 may be recognized by the cells of their cuticle, with their long, firmly interlocking, 

 jagged projections (Fig. 76). Between the latter cells are found simple round 

 cells which come to view after treatment with caustic solutions (p. 141). 



The refuse of button manufacture from the ivory nut, Phytelephas macrocarpa, 

 has no feeding value. The comparatively thin seed coat consists of sclerenchymat- 

 ous cells, prominent among which are the outer spindle-shaped cells. Beneath the 

 seed coat lies the well-developed endosperm (£). It consists of cells with ex- 

 ceptionally thick walls with peculiar buttonlike pores at the base. 



Fig. 81. Corn cockle seeds. 

 a, Natural size; b, X 12. 



Fig. 80. Corn cockle. 

 1, Flower stem; 2, longitudinal section of flower; 

 3, longitudinal section of ovary with stig- 

 ma; 4, cross section of flower. 



Sawdust Stains yellow upon addition of caustic potash solution and is easily 

 recognized with the unaided eye or by means of low magnifying power. In sawdust 

 from Coniferae the microscope reveals chiefly the characteristic tracheids and medul- 

 lary ray cells. Parenchymous cells, except in the fir {Abies, y^g. 79) are less 

 frequently met with. In sawdust from deciduous trees libriform tissues predominate. 



Feed meals and brans are frequently adulterated with screenings. The latter 

 consist of all kinds of weed seeds, broken grains of the cereals, ergot, spores of 

 fungi, chaff, maggots, beetles, mouse excrement, particles of earth, sweepings, etc. 



Weed seeds are usually easily recognized by their brown, blackish and often 

 rough seed coats. They occur in the screenings and are often ground up and mixed 

 with meals but chiefly with bran. 



