SEEDS. 



135 



PLATE'LVIII. 



FIG. 68. Powdered White Mustard 



am, Large mucilaginous cells of epidermis in surface view, showing 



concentric striation 



ap, Isodiametric cells of proteid layer, containing aleurone grains. 

 a'p', The same, with membranous layer of seed-coat adhering. 

 cm, Membranous layer. 

 co, Cells from outer part of cotyledons. 

 c'o', Cells from inner part of cotyledons. 

 col, Collenchymatous cells. 

 ec, Epidermis of cotyledons. 

 pa, Tissue of radicle. 

 sc, Sclerenchymatous layer, surface view, 

 3'c', The same in profile, 



