ON ACALEPHA. 569 
phosphorescent, produced no effect of urtication. The spe- 
cies which possess this property in the living state, have it 
also when dead. Certain others possess it in so small a de- 
gree, that it becomes sensible only in the softest parts of the 
skin. 
Attempts have been made to ascertain whether the medusx 
are susceptible of a reproduction of the parts which have 
been removed from them; but such does not appear to be 
the case. 
The medusz serve as food to several other animals. The 
actiniz seize these acalephe on their passage, and draw them 
by degrees into their stomach. The whales also destroy an 
immense quantity of them ; but it appears that these are spe- 
cies or individuals of an exceeding smallness, with which the 
waters of the sea, inhabited by these great animals, are filled, 
and that they are there with many other animals of different 
types, but which are likewise almost microscopic. 
The PHYSALI®, which constitute the type of the second 
division of acalepha, are a very singular race of animals, no- 
ticed for a long time by sailors, who give them the names of 
galleys, frigates, or even ships of war, in consequence of the 
elegant manner in which they seem to sail on the surface of 
the waters. They have received the name of physalie, or 
sea-bladders, in consequence of their resemblance to a bladder, 
or even that of sea-nettles, because it appears that they pro- 
duce the same effect upon the skin as the meduse. Some 
recent writers have thought proper to place them among the 
mollusca; and certain it is, that they present little or nothing 
of the radiated arrangement; but as the Baron observes, the 
total absence of internal and complicated organs, of which he 
has satisfied himself in many large individuals, will not al- 
low us to admit of the notion that the physalia may be one of 
the mollusca. 
