l82. 



THE STRUCTURE OF ECONOMIC PLANTS 



In Allium Cepa, the thick-walled epidermal cells are filled with 

 a very dark brown pigment; and the parenchymatous layer is 

 similarly colored, consisting of six rows of thin-walled cells that 



f 



.^ri^wery 



Fig 8i A the inflorescence ; B and C, the inner and outer stamens ; D, a single flower in 

 side section; £, the same, face view; f, flower with perianth removed; G, floral diagram 

 showing arrangement of parts. 



are flattened tangentially, and roughly oblong in surface view. 

 (Fig. 84, A, B.) The layer of perisperm that underlies the paren- 

 chymatous 'layer is hyaline, and the seed is filled with a horny 



