GENUS ANTHOPHYSA. 267 



two in number, one considerably longer than the other; no distinct mouth, 

 food being incepted at any point of the periphery ; an endoplast and one 

 or more contractile vesicles usually conspicuous. Inhabiting fresh water. 



Anthophysa vegetans, Miiller sp. 

 PL. XVII. FIGS. 13-26, AND PL. XVIII. FIGS. i-io. 



Bodies irregularly pyriform, obliquely truncate anteriorly, slightly com- 

 pressed ; attached in rosette-like clusters of fifty or sixty or more zooids 

 to the terminations of an irregularly branching, and in the more robust 

 condition erect, dark brown, longitudinally striate, horn-like pedicle ; this 

 pedicle in weakly or overgrown examples simply granular and highly 

 flexuose ; contractile vesicles two or more in number, posteriorly located ; 

 endoplast spherical, subcentral. Length of bodies 1-4000" to 1-3500". 



HAB. Fresh water, abundant. 



Among the earlier writers there has been a general tendency to confound the 

 animalcules of this species first described by Miiller under the title of Volvox 

 vegetans, but since more generally known by Bory's title of Anthophysa Mulleri 

 with Uvella, this view being even reproduced and adhered to in Pritchard's ' History 

 of the Infusoria,' ed. iv., 1861, and yet more recently in De Fromentel's ' FJtudes sur les 

 Microzoaires.' Such widespread but mistaken opinion as to the affinities of Antho- 

 physa has no doubt arisen from the considerable resemblance in mere outward form 

 subsisting between the detached rosette-like clusters, or " coenobia " as they are desig- 

 nated by Stein, of the present species and the permanently free-floating spheroidal 

 colonies of the genus Uvella and its allies. Ehrenberg indeed, regarding the floating 

 clusters and attached colony-stocks as independent organisms, conferred upon the 

 latter the title of Epistvlis vegetans and on the former that of Uvella uva and U. chama- 

 morus. The Uvella-like aspect of the floating clusters is nevertheless purely superficial, 

 the individual zooids exhibiting, on closer examination, an essentially distinct type of 

 structure. In further illustration of the diversity of opinion that originally prevailed 

 concerning the nature and affinities of Anthophysa, it may be mentioned that Bory 

 de St. Vincent referred it to that doubtful organic group " le regne Psychodiaire" 

 proposed by him for the reception of all such types as appeared, with the means 

 then at disposal for their investigation, to form an intermediate link between the 

 animal and vegetable kingdoms.* 



By M. Kiitzing Anthophysa vegetans was regarded as a true plant or aquatic 

 fungus of which the branching stem represented the mycelium, and the terminal 

 groups of monads the reproductive bodies or zoogonidia. Viewing it from this 

 aspect this authority placed it among other fungi, and conferred upon it the generic 

 name of Stereonema. That the branching stems or zoodendria of this social monad 

 bear a strong likeness to the mycelium of certain cryptogamic types, is not to be 

 denied, more especially as this portion of the organism, usually of a rusty brown 

 hue, is frequently found thickly encrusting aquatic plants without presenting any trace 

 of the clusters of animalcules which in the perfect condition terminate, and originally 

 constructed, each compound branchlet, but subsequently falling away have left but 

 the naked stalks. This circumstance, as explained by Claparede and Lachmann, 

 who unfortunately only succeeded in obtaining the species in such imperfect state, 

 doubtless gave rise to Kiitzing's opinion of its fungoid character, he accepting the 

 naked branching stalk as the primary portion destined to produce, as an aftergrowth, 



* Bory, by the establishment of this transitional organic group, may be said to have completely 

 anticipated Haeckel in his comparatively recent creation of a propose! kingdom of the Protista, 

 already referred to at page 44. 



