DIONMA. 



[chap. 



mutual advantage. The honey of the flowers affords 

 to the insects a rich and nutritious food ; and if the 

 latter rob the flowers of some of their pollen, they 

 make ample amends by carrying a portion of the 

 remainder from one flower to another, and thus con- 

 ferring on the plant the great advantage of cross- 

 fertilisation. In Drosera (Fig. 8i), on the contrary, 

 we find a very different state of things, for the plant 



Fig. 82. — Two leaves of Diousea : one open, one closed upon a fly. 



catches and devours insects. This genus, and the 

 other plants which have this remarkable habit, have 

 recently been the subject of an admirable memoir, 

 by Dr. Hooker, read before the British Associa- 

 tion [Nature, Sep. 3, 1874). The first observation 

 on insect-eating flowers was made, about the year 

 1768, by our countryman Ellis, on Dionsea, a North 

 American plant, the leaves of which have a joint 



