198 GENEKAL HISTORY OF THE INFUSOEIA. 



imperfectly developed ; hence Mr. Carter allies this genus rather with the 

 zoospores or gonidia of Algae, and assumes that it must, like other mouthless 

 organisms, derive its nutrition through endosmosis. Cohn, on the other 

 hand, although cognizant of many plant-like features in Euglena, cannot ac- 

 quiesce in detaching it from animalcules, because of its great contractihty 

 and of the fact that there are undoubted animals, such as Opalina, Rhizojwda, 

 Gregarina, Trematoda, &c., which want the special animal characteristic of a 

 mouth. 



Mr. Carter would, it seems, recognize both Euglena and Astasia as close alhcs 

 with Amoeba, — an affinity remarked by Ehrenberg, who placed the family As- 

 tasioia between Chsterina and Amoeba^a, treating the variability of the form of 

 the body as a leachng characteristic. Indeed, the first-named observer alludes to 

 an actual transition of Astasice into Amcebce, in the following paragraph {A. 

 N. H. xvii. 1856, p. 115): — '' Young Astasice are developed within the cells 

 of Spirogyra to a great extent ; and although they at first have almost as 

 much polymorphism as an Amoeba, still they retain their cilium, and after a 

 while assimie the form and movements pecuhar to Astasia. I might here 

 mention that on one occasion I saw" a lay^ge Amoeba with a long cilium at one 

 time assuming the foim of Astasia, and at another that of Amoeba, which thus 

 gives us the link between these two Infusoria. The cilium, however, had not 

 the power of the filament of Astasia, though it occasionally became terminal." 

 At a previous page, a rhizopodous development of the contents of Euglena; 

 into granuliferous Amoeba; of a pinkish colour has been adduced as a fact 

 noticed by the same observer. 



We need not stay to examine the vital endowments and habitats of the 

 Astasice ; for, except the facts occuiTing in the preceding history of the family, 

 and in the general account of Phytozoa, there is nothing important to adduce. 



