Chap. XFV. 



ALDROVANDA VESICULOSA. 



323 



is slightly concave, and is formed, according to Cobn, 

 of three layers of cells. Its upper surface is studded 

 with colourless glands like, but more simple than, 

 those of Dioneaa; they are supported on distinct 

 footstalks, consisting of two rows of cells. The outer 



Fig. 13. 

 {Aldrovanda vesiculosa.) 

 Upper figure, whorl of leaves (from Prof. Cohn). 

 Lower figure, leaf pressed flat open and greatly enlarged. 



and broader portion of the lobe is flat and very 

 thin, being formed of only two layers of cells. Its 

 upper surface does not bear any glands, but, in their 

 place, small quadriiid processes, each consisting of 

 four tapering projections, which rise from a common 



