Quarterly journal of microscopical science . the accessory glands (ootype, shell-gland, &c.) of Neritacea which have been described by Bourne (3). The cavity of the vagina is continuous with those of theglands. (3) Male Organs (Text-fig. 11). The testis consists of a numbor of branching follicular tubesand in general plan resembles the ovary. Only one kind of 180 GUY C. ROBSOX spermatozoon was found, viz. the typical . The definitivestage of the latter, which is found in the vas deferens andthe receptaculuni seminis of the female, exhibits anelongate conical head , a usually well-developed acr
Quarterly journal of microscopical science . the accessory glands (ootype, shell-gland, &c.) of Neritacea which have been described by Bourne (3). The cavity of the vagina is continuous with those of theglands. (3) Male Organs (Text-fig. 11). The testis consists of a numbor of branching follicular tubesand in general plan resembles the ovary. Only one kind of 180 GUY C. ROBSOX spermatozoon was found, viz. the typical . The definitivestage of the latter, which is found in the vas deferens andthe receptaculuni seminis of the female, exhibits anelongate conical head , a usually well-developed acrosome,an acute apical portion, no discernible middle-piece, and anelongate tail. The precise length of the latter could not bevery satisfactorily ascertained, but it is apparently verymuch longer than that of Bythinella, in which the tail isbetween twice and thrice as large as the head. In P. ulvaeand P. t aylori (Eobson MS.) the tail is relatively of the constant features of spermatogenesis is the occur- Text-figs. Fig. 11.—Section of penis, a, freeportion of appendage ; vd, vasdeferens.
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Keywords: ., bookcentury1800, bookdecade1850, bookpublisheroxfor, bookyear1853
