Page:An introduction to physiological and systematical botany (1st edition).djvu/366

 336 fruit comes to maturity at the bottom of the water. All this Micheli has described, without being aware of its final purpose; so different 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 office in that situation, as Chara, ''Engl. Bot. t. 336, &c.; as well as the Fucus and Conferva'' 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 Sycomore, Ficus Sycomorus. In this genus the green fruit is a hollow common calyx, or rather receptacle, lined with various 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 perfected, 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 very curious observation is recorded by