ZOOPHYTES 383 



multitude of objects grouped together to constitute a sin- 

 gle animal, their variety in form, and the sympathy 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 peri- 

 pheric prolongations; the alimentary polypes, some white 

 and filiform, others thick, fleshy, crimson, or yellow sacs, 

 obligingly everted, to expose their interior to our micro- 

 scopic eye; the reproductive polypes, with their richly-col- 

 ored 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 inflicted on the body to 

 which they are attached; and, lastly, the tentacle polypes, 

 floating in the water like long and slender threads of gos- 

 samer, or dragging up heavy loads of food for the common 

 good; these, together with the intimate relation and sym- 

 pathy subsisting between the polypary and its associated 

 organs, all combine to form an object of the highest inter- 

 est, and indicate that, in this fixed yet travelling zoophyte, 

 we have a type of structure transitional between the den- 

 dritic Hydroidaz and the more highly organized Acaleph. 

 In the simplest acalephoid form, such as the medusoid of 

 Companularia [or Laomedea] (which is nothing more than 

 an extension of the polypary specially organized for inde- 

 pendent and motile life), we have (as in Hydractinia) an 

 expanded polypary, represented by the umbrella, and per- 

 meated by vascular tubes from the confluence of which 

 last spring, at the centre, the tentacular polypes, various 

 in number; and between them the reproductive polypes, 

 represented by the sessile generative sacs." ' 



1 Ibid., op. cit. 



