OF THE PHTTOZOA. 135 



The genus Anthophysa (XXYI. 2) has been more particularly studied by 

 Dujardin and Cohn. Ehrenberg pro\dsionally placed it among the Vortlcel- 

 lina as a doubtful species of Ejpistylis, as he was unable to determine whether 

 it possessed a wreath of cilia at its head or only a single filament : if the 

 latter, he remarked, it would belong to the Monads. Mtiller, its discoverer, 

 had indeed more rightly seized on its true position by associating it mth 

 Volvox. Dujardin subsequently made out its affinity with Uvella, and adopted 

 M. Boiy de St. Vincent's generic appellation for it. In this determination of 

 its position Dujardin has the weighty support of Cohn, who has recently sub- 

 mitted it to careful examination. Dujardin's description is very accm-ate, and 

 will serve our purpose. '' It is very difficult," he writes, " to distinguish a 

 Uvella from a free Anthophysa ; but no difficulty will exist if some of the 

 branching supports of the latter are seen in the siuTounding fluid. These 

 supports have an arborescent figure irregularly branched, are brownish at the 

 base, but clearer and even diaphanous at the extremities of the branches, 

 which are themselves nodular or rugged ; they are secreted by the animals, 

 and are found affixed to the sides of the vessel in which water containing 

 these Infusoria has been but recently placed. Each group of animalcules is 

 at fii^st fixed on the diaphanous extremity of the branch which it has secreted 

 (XXYI. 2) ; but any agitation of the liquid, or sudden shock, easily detaches 

 it, and it then moves in a revoMng manner in the hquid. This movement is 

 the result of the simultaneous action of the flagelliform filaments with which 

 each individual of the colony is provided. When, moreover, a group has been 

 detached, whether accidentally or spontaneously, isolated individuals may be 

 seen moving about precisely like Monads with a single filament. The branch- 

 ing support is at first soft and glutinous, but gradually acquires consistency 

 and a brownish and homy aspect, when it seems no longer to participate in 

 the life of the animalcules, and recalls to the mind the construction of the 

 fibrous skeleton of certain sponges. It is conceivable either that the branches 

 themselves bifurcate, or that the division is the consequence of the multipli- 

 cation by fission of the groups of animalcules." 



Cohn has little to add to this account. He describes the probably chitinous 

 stem to be invested externally by a brownish mucilaginous layer ; and also 

 finds that from 2 to 8 and fi'om that to 20 Monads may be aggregated at the 

 extremity of the branches. Frequently a branch is bare at its point, having 

 lost its animal colony ; and it would seem that the whole of the groups are 

 in succession throvm off and dispersed as free Monads and as UveUa-like 

 groups. Cohn, indeed, intimates his belief that Uvella and Anthophysa are 

 not actually distinct genera, but mere representatives of two conditions of 

 the same animalcule. Unlike Ehrenberg, he failed to get indigo -particles taken 

 up by the Uvella-like beings. 



Before arriving at the conclusion that Anthophysa is no other than Uvella 

 Uva seated on a branching stem, and of animal nature, he canvasses the 

 question if this organism be not rather the mycchum of a Fimgus bearing its 

 spores at the extremities of its branches, and decides against the supposition 

 chiefly from the irregular and indefinite multiplication of the monadiform 

 members of the groups, from the detachment of these en masse instead of by 

 separate spores, and from the want of evidence to show that, when these 

 UveUa-like groups are detached, they assume the quiescent or ' still ' condition, 

 and germinate into an arborescent mycelium like the parent, to develope in its 

 turn terminal masses of spores. 



The branching stem has been described by Kiitzing and others as a micro- 

 scopical Fungus (Conferva), under the name of Stereonema, and several species 

 instituted ; but Cohn points out its analogy with the pedicle of Gomphonema 



