FLOURS. 



27 



PLATE X. 



Fig. 20. Wheat FJour. (x 240. 



a, a', Starch grains without evident hilum, larger than barley starch, smaller 

 than rye starch. 



a.1, Aleurone. 



ap, Aleurone layer. 



b, Brown layer. 



co, Debris of cotyledon. 



Ct, Transverse cells with pitted walls, surface view. 



C' t', Transverse cells,^ section. 



e, e', Outer epidermis of pericarp with thickened and pitted cell icalls 



ec, Scutellum. 



es, Epidermis of scutellum. 



ffv, Debris of the flbro-vascular bundle of the raphe. 



h, Cells of the hyaline layer. 



p. Hairs, entire or broken, with lumen rather abruptly enlarged at the base. 



pi, Cells with brown pigment. 



sc, Lignified cells of the hypoderma with pitted walls. 



t, Tubular cells, surface view. 



