ZOOPHYTES, 339' 



which subsists between the different parts. The singular 

 spinous skeleton; the expanded membrane of the polypary, 

 with its beautiful internal network of tubes and delicate 

 peripheric prolongations; the alimentary polypes, some 

 white and filiform, others thick, fleshy, crimsoD, or yellow 

 sacs, obligingly everted, to expose their interior to our 

 microscopic eye : the reproductive polypes, with their 

 richly coloured generative sacs ; the sessile generative 

 organs of the polypary; the ophidian polypes, coiled in 

 neat spirals when at rest, but starting into furious action, 

 like a row of well-drilled soldiers, when injury is in- 

 flicted on the body to which they are attached; and lastly 

 the tentacle polypes, floating in the water like long and 

 slender threads of gossamer, or dragging up heavy loads of 

 food for the common good; — these, together with the inti- 

 mate relation and sympathy subsisting between the 

 polypary and its associated organs, all combine to form 

 an object of the highest interest, and indicate that, in 

 this fixed yet travelling zoophyte, we have a type of struc- 

 ture transitional between the dentritic Hydroidce and the 

 more highly organised Acaleph* In the simplest acale- 

 phoid form, such as the medusoid of C omjianularia [or 

 Laomedeaj (which is nothing more than an extension of 

 the polypary specially organised for independent and 

 motile life), we have (as in Hydractinia) an expanded 

 polypary, represented by the umbrella, and permeated by 

 vascular tubes, from the confluence of which last spring, 

 at the centre, the tenticular polypes, various in number; 

 and between them the reproductive polypes, represented 

 by the sessile generative sacs."f 



You see here a jar, on the glass side of which are traced 

 a number of very fine white lines, barely discernible by 



* From the Greek aicaXiifyr) (akalephe), a nettle, applied to animal 

 known under the common name of •jelly-fishes and sea-nettles, from 

 their causing the sensation of stinging when handled. 



f Dr. Wright, op. cit. 



z 2 



