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CYSTOSPEltMEiE.

founded upon a partial, imperfect, and often inaccurate know-ledge, and therefore not admissible. If any of the olderterms should be retained for the genus Vesiculifera, it shouldbe by right of priority, — Conferva, for this genus hithertohas been made to embrace various species of Vesiculifera, aswell as certainly a heterogeneous mass of other productions;but it seems to me that this genus ought to be abolishedaltogether, and that the term Conferva should be used in amore extended sense, and applied generally to any species ofthe confervoid Alga , in the same manner as the word zoo-phyte is now used. Kiitzing, in his “ Phycologia Generalis,”confines the genus Conferva to certain species of Spharoplea,and to the marine species of Conferva, with simple filaments,such as Conf. area and its allies. Next to Conferva, Prolifer a

and who observes that the Zoocarpea of Nees of Esenbeck, “Nov. Act.Nat. Cur.” an. 1813, p. 517., is the same genus. The same authorthinks that the greater part of the Prolifere of Vaucher, also the CEdo-gonium of Link, ought to constitute part of the genus Tiresias . OfTiresias , Bory gives the following description : ‘ Filaments cylindrical,the interior tube filled with green colouring matter, in which are de-veloped hyaline corpuscles which separate from the filaments. Thiscolouring matter ends by becoming agglomerated in each cell into asphere or zoocarpe, of appearance similar to the gemmse of the Con-jugate, and inert up to the moment when rupturing the cell by itsdevelopement, and, putting itself in contact with the surrounding fluid,it commences to move itself in different directions, and finishes^by swim-ming freely about, leaving all broken and transparent as water the tubewhich produced it.’ The Conferva bipartita of Dillwyn is certainly aspecies of Tiresias , in the vegetable condition of which the Cercariapodura and viridis of Muller are the Zoocarpes, which we have seenafter a certain period of liberty fix themselves by their divided extremitiesupon the remains of vegetables, or even upon the filaments of otherTiresias , and elongate themselves into a confervoid vegetable. Thisstate of elongation has been well seen and figured by Le Clerc, in hisexcellent memoir on the Proliferce of Vaucher, as well as by Dillwynupon his Conferva genuflexa. It is surprising that these skilful naturalistshad not detected the metamorphoses of the Enchalis into that which theycall Conferee .”

Both Bory and M. Leon le Clerc are in error in supposing that theyhad witnessed the developement of the large oval or spherical bodiesformed by the concentration of the endochrome of two cells: what thelatter represents are undoubtedly the zoospores in different stages ofgrowth.