399 



CLASS V. POLYPI.* 



As we draw near the confines of the animal world, 

 it is interesting to observe how closely many of the 

 subjects of consideration approach to vegetables, not 

 only in the simplicity of their structure, but even 

 in their forms, colours, and general appearance. We 

 have already seen some illustrations of this resem- 

 blance in the Echinodermata , but, in the present 

 Class, much lower in the scale than they, the likeness 

 is so great that many of them were arranged by 

 the older naturalists with plants ; and some of the 

 very lowest have been, even in the present day, 

 and among eminent zoologists, subjects of dispute 

 as to their appropriate situation. 



These animals usually consist of a cylindrical 

 body, open at one extremity, around which open- 

 ing are placed several simple tentacles, varying 

 greatly in number and form. They generally con- 

 sist of an uniform jelly-like substance, without any 

 internal vessels save the single cavity of the body ; 

 a few have other vessels, but even these are without 

 coats, being merely hollowed out of the jelly-like 

 flesh. Almost all are capable of multiplying their 

 race by sending out shoots in the manner of buds, 

 and also by the separation of their bodies into parts 



polys, many, and vous,pous, a foot. 



