FLOURS. 



37 



PLATE XV. 



Fig. 25. Maize Flour, (x 240.) 



a, Rounded grains of starch from the mealy part. 



a', Angular starch from the horny part. 



ap, Aleurone layer; the cell walls readily swell in water, more readily 

 still in caustic potash. 



co, Cotyledon. 



ct, Transverse cells, often irregular, separated from one another and 

 resembling the tubular cells which they cross at right angles. 



e, Outer epidermis of pericarp. 



ec, Scu tell vim. 



ge, Masses of starch from the horny part. 



gi, Masses of starch from the mealy part. 



me, mi, Layers next to the epidermis. 



pa, Branching ceils with lacuna. 



t, Tubular cells, very numerous. 



