336 ASSISTAI^CE OP INSECTS IN IMPREGNATION. 



fruit comes to maturity at the bottom of the 

 water. All this Micheli has described, with- 

 out being aware of its final purpose ; so dif- 

 ferent is it to observe and to reason ! 



Some aquatic vegetables, which blossom 

 under water, seem to have a peculiar kind of 

 glutinous pollen, destined to perform its of- 

 fice in that situation, as Chara, Engl. Bot. 

 t. 336, &c.; as well as the Fiicus and Con- 

 ferva tribe ; but of the real nature of the 

 fructification of these last we can at present 

 only form analogical conjectures. 



The fertilization of the Fig is accomplished 

 in a striking manner by insects, as is that of 

 the real Sycamore, FicvH Sj/comonis. In this 

 genus the green fruit is a hollow common 

 calj^x, or rather receptacle, lined with vari- 

 ous flowers, seldom both barren and fertile 

 in the same fig. This receptacle has only 

 a very small orifice at the summit. The 

 seeds therefore would not in general be per- 

 fected, were it not for certain minute flies of 

 the genus Ci/nips, continually fluttering from 

 one fig to the other all co\ ered with pollen, 

 and depositing their eggs within the cavity. 



A very curious observation is recorded by 



