104 HYDEOZOA. 



require such instruments of sense, to enable it to select a situation 

 adapted to the reception of the new colony to which it gives birth : 

 when once it has made choice of a fit locality, such organs become as 

 useless as they were formerly needful, seeing that all the functions of 

 life are restricted to those of alimentation and reproduction. 



(266.) The young Campanulariae, arrived at this stage of develop- 

 ment, abandon the ovarian vesicle of the parent polypary and swim 

 freely about in the surrounding medium, exactly resembling so many 

 young Medusae (fig. 48, G). 



CHAPTER VI. 



HYDEOZOA (continued). 



ACALEPHJE (CllV.). 



(267.) THE ocean, in every climate, swarms with infinite multitudes of 

 animals which, from their minuteness and transparency, are almost as 

 imperceptible to the casual observer as the Infusoria themselves ; their 

 existence, indeed, is only indicated by the phosphorescence of some spe- 

 cies, which being rendered evident on the slightest agitation, illuminates 

 the entire surface of the sea. All, however, are not equally minute, some 

 growing to a large size ; and their forms are familiar to the inhabitants 

 of every beach, upon which, when cast up by the waves, they lie like 

 masses of jelly, melting, as it were, in the sun, incapable of motion, and 

 exhibiting few traces of organization, or indications of that elaborate 

 structure which more careful examination discovers them to possess. 

 Their uncouth appearance has obtained for them various appellations by 

 which they are familiarly known, as Sea-jelly, Sea-blubber, or Jelly- 

 fishes ; whilst, from disagreeable sensations produced by handling most 

 of them, they have been called Sea-nettles, Stingers, or Stang-fishes. The 

 faculty of stinging is indeed the most prominent feature in their history ; 

 so that their names in almost all languages are derived from this cir- 

 cumstance. They were known to the older naturalists by the title of 

 Urticce marince ; and the word at the head of this chapter, applied by 

 Cuvier to the entire class, and originally used by Aristotle, is of similar 

 import (a/caXr/0?7, a nettle). 



(268.) There are few subjects which come under the observation of 

 the physiologist more calculated to excite his astonishment than the 

 history of these creatures. If he considers, in the first place, the com- 

 position of their bodies, what does he find ? An animated mass of sea- 

 water ; for such, in an almost literal sense, they are. Let him take an 

 Acaleph, of any size, and lay it in a dry place ; it will be found gradually 

 to drain away, leaving nothing behind but a small quantity of trans- 

 parent cellular matter almost as delicate as a cobweb, which apparently 



