RADIATES., 347 
602. The Hydra is nothing but a stomach with tenta- 
cles attached to it. It can be turned inside out like a 
glove, and fare as well as before, showing that there is 
little, if any difference between what may be called its 
skin and its inside lining. Trembley, the first discoverer 
of the Hydrz, once witnessed a very singular circum- 
stance: “* Two Polypes had seized upon the same animal ; 
both had partially succeeded in swallowing it; when the 
largest put an end to the dispute by swallowing its op- 
ponent, as well as the subject of contention. ‘Trembley 
naturally regarded so tragical a termination of the affray 
as the end of the swallowed Polype’s existence; but he 
was mistaken; for, after the devourer and his captive 
had digested the prey between them, the latter was re- 
gurgitated, safe and sound, and apparently no worse for 
—the imprisonment.” 
~~ 603. Hydras are produced in two ways. One is by 
seeds or eggs. These are thrown out by the animal in 
the autumn in the form of gelatinous globules, and in the 
following spring Hydras come from them, and, fastening 
themselves to some stick or other solid substance, begin 
their quiet but predaceous life. Another mode of pro- 
duction is by buds, thus allying these animals in a marked 
manner to plants. Buds at first appear as slight projec- 
tions from the outer surface of the body, and these grad- 
ually become perfect animals, at length separating from 
the parent to attach themselves to some solid body. The 
stomach of the young Polype communicates with that of 
the parent so long as they are connected together; and 
yet it is not uncommon to see both struggling for the 
same worm, and gorging opposite ends of it. Sometimes 
the young Hydra has buds start out from its body before 
it has separated from the parent, so that we have three 
generations in one group. This production of different 
generations is so rapid in some cases, that it is calculated 
that above a million descendants come from one animal 
in a month. 
