iSISTANCE OF INSECTS IN IMPREGNATtOV, 



fiftut 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. 

 L 336, &c; as well as the Fucus and Con* 

 fcrva tribe : but of the real nature of the 

 fructification of these last we can at present 

 cnly form analogical conjectures. 



The fertilization of the Fig is accomplished 

 in a striking manner by insects, as is that of 

 the real Sycomore, Ficus Sycomorus. In this 

 semis the green fruit is a hollow common 

 calyx, 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 Cynips, continually fluttering from 

 one fig to the other all covered with pollen, 

 and depositing their eggs within the cavity. 



A verv curious observation is recorded by 



