File:Lectures on the comparative anatomy and physiology of the invertebrate animals - delivered at the Royal College of Surgeons (1855) (14780789711).jpg

Identifier: lecturesoncompar02owen (find matches)
Title: Lectures on the comparative anatomy and physiology of the invertebrate animals : delivered at the Royal College of Surgeons
Year: 1855 (1850s)
Authors: Owen, Richard, 1804-1892
Subjects: Invertebrates Anatomy, Comparative
Publisher: London : Longman, Brown, Green & Longmans
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

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rm-reservoir, where the sperm-duct quits the base of the albuminiparoussac, and this latter may be regarded as a more special dilatation of theoviduct, with follicular walls. The sperm-duct, enlarged and withmore glandular walls (t\ now proceeds with many short folds parallelwith the uterus to the base of the penis. This is a long and slenderorgan (v), usually retracted and concealed within the visceral cavity,but, like the finger of a glove, capable of being everted and protrudedexternally. The so-called uterus (u) is a long canal, with trans-versely plicated glandular walls, terminated by a vagina opening intothe common genital vestibule, the external orifice of which is nearthe mouth of the respiratory sac, on the right side of the head.With the vagina there communicates the duct (z) of a small pyriformvesicle (z), which is a sperm-reservoir, for the fecundating element ofanother individual received in coitu. A small caecum is developed * CCCXIII. p. 370. t CCCLXIV. p. 378. o o 562
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Helix pomatia, dissected. from the duct in Helix pomatia, and a very long one in Hdix ai-bus-torum: the duct is short and simple in the slug (Limax). Thegenital vestibule receives the terminal outlets of two groups ofbrrnched ceeca (x, x), or multifid vesicles, the function of which isunknown. But the complexity of th^ generative apparatus does notend here : the snail is provided with a pyriform muscular sac (y), theaperture of which terminates close to the generative outlet. Theexpanded base or head of a slender conical calcareous style or dart(6, in the detached figure) is attached to the fundus of the sac (a) jits sharp apex (c) extends close to the orifice, and by the contractionof the sac it can be protruded outwards. With it the snails pierceeach others skin, and the function of this curious organ would seemto be to cause a preliminary excitement to the reciprocal union of thetwo androgynous individuals. PTEROPODA AND GASTROPODA. 563 The modifications of the parts of the complex

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