Elements of comparative anatomy (1878) Elements of comparative anatomy elementsofcompar00gege Year: 1878 Fig. 206. Asexual form of Sal pa piunata (solitary form), n Em. bryo-cbain escaping to the ex. terior. Fig. 207. Sexual form of Sal pa pinna t a (chain form), t Connecting bar. a Incurreut orifice. b Excurrcnt orifice. c Ganglion. d Gills. / Heart, h Ventral groove, r Hepatic pouch. vim Embryo with embryonic organs (both figures after C. Vogt). This arrangement brings about an ' alternation of generations,' seeing that the forms provided with a stolon are always permanently devoid of sexua
Elements of comparative anatomy (1878) Elements of comparative anatomy elementsofcompar00gege Year: 1878 Fig. 206. Asexual form of Sal pa piunata (solitary form), n Em. bryo-cbain escaping to the ex. terior. Fig. 207. Sexual form of Sal pa pinna t a (chain form), t Connecting bar. a Incurreut orifice. b Excurrcnt orifice. c Ganglion. d Gills. / Heart, h Ventral groove, r Hepatic pouch. vim Embryo with embryonic organs (both figures after C. Vogt). This arrangement brings about an ' alternation of generations,' seeing that the forms provided with a stolon are always permanently devoid of sexual organs. On comparing this series of phenomena with that occurring in the Ascidia), we find, just as in the Ascidia3, proliferous outgrowths, namely, the stolons. The outgrowth in question is here confined to a definite part of the body. In Pyro- soma a proliferous stolon is present, sunk in the mantle, and from every such stolon only a single bud is developed; side by side with this are developed sexual organs. Accordingly it is not possible to suggest that the stolon belongs to the sexual apparatus. In the Salpac and in Doliolum, contrary to what we find in Pyrosoma, the proliferous stolons give rise to copious generations of buds. In this case, however, the absence of a sexual apparatus is the accompani-
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