Lectures on the comparative anatomy and physiology of the invertebrate animals : delivered at the Royal College of Surgeons . and the Pectinibranchiata. In these the intromittent organ isusually of extraordinary length : it is grooved in most, perforated ina few ; capable of retraction in the Paludina, but doubled back uponthe outside of the mantle when drawn into the shell by the Buccinumand Strombus. In the Carinaria it is bifid. The internal organs of the male whelk, represented in the annexedfigure, consist simply of a testisand sperm-duct. The testis («) isof considerable size, sharing wi
Lectures on the comparative anatomy and physiology of the invertebrate animals : delivered at the Royal College of Surgeons . and the Pectinibranchiata. In these the intromittent organ isusually of extraordinary length : it is grooved in most, perforated ina few ; capable of retraction in the Paludina, but doubled back uponthe outside of the mantle when drawn into the shell by the Buccinumand Strombus. In the Carinaria it is bifid. The internal organs of the male whelk, represented in the annexedfigure, consist simply of a testisand sperm-duct. The testis («) isof considerable size, sharing withthe liver the smaller convolutionsof the shell ; from this arises thevas deferens, which forms by itsconvolutions a kind of epididymis{b), and then increasing in dia-meter enters the root of the penis,through which it passes by a tor-tuous course (d) to the tubercle atthe extremity of this organ, whereit opens externally. The penis iscomposed of strong transverse fas-ciculi of muscle, with lacunar sinu-ses, which together cause the erec-tion of this organ: the muscles will at the same time lengthen it, and o o 2 208. Male organs of Buccinum. 564 LECTURE XXII. Straighten the zig-zag turns into which the vas deferens is thrown inits usual relaxed state. In the female the position of the testicle is occupied by the ovary,while the vas deferens is represented by a thick and glandularoviduct. There is no rudiment of exciting organ (clitoris) : the ge-nerative aperture is situated a little within the edge of the branchialcavity, and is a simple hole leading to the oviduct.* In Murcx the penis is proportionally smaller; and, instead of acomplete vas deferens, penetrating to its extremity, there is merely agroove along its surface, along which the semen flows. In Volutathe exterior groove only runs to the base of the penis, and inStrombus the male organ is a mere tubercle. In the Pulmonalia operculata the organs of both sexes are in everyrespect similar to those of the Pectinibranch
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Keywords: ., bookauthorowenrichard18041892, bookcentury1800, bookdecade1850
