VALLISNERIA. 
259 
casual observer ; but when proper attention is paid 
to its curious formation, we cannot fail to be struck 
with the evident marks of contrivance which are 
manifested in the propagation of the species. 
Nature has ordained that the male flowers should 
be produced at the bottom of the water, while the 
flower of the female plant floats on the surface, and 
is furnished with an elastic spiral stalk, which is 
connected to the root at the bottom, and extends or 
contracts as the water rises or falls. In rapid rivers 
this contrivance becomes especially necessary ; and 
m the Rhone, where these plants are to be met 
with, the difference often amounts to several feet in 
a few hours, on account of the torrents which flow 
into it. The circumstance which so greatly raises 
our astonishment is this : the male flowers which 
are produced under water have the power to detach 
themselves from the plant and rise to the surface 
whenever the farina is ripe, where the female flowers 
are certain at that time to be in bloom, and ready 
to receive them. 
Thus is this essential process conducted, and in 
this manner has Nature contrived to fulfil her in- 
tentions in situations where the difficulties to be en- 
countered seem almost insurmountable. 
