. A manual of zoology. Zoology. 310 LL use A. of tlio pericardium around the systemic and brancl]ial hearts and tlie thin- wallt'd genital sac, one wall of whicli Vjears the genital ducts, while on the other the sexual cells arise or the ducts of a separate sexual gland oiien (fig. 392). The gonads of the always dioecious CeiAalopoda are unpaired and lie far back in the visceral sac. The ducts in the female Octopoda (rarely in the males) and in some Decapoda (Oic{opsida) are paired. In Nautilus only the right duct is. functional in either sex, although the left is well developed. Elsewhere the
. A manual of zoology. Zoology. 310 LL use A. of tlio pericardium around the systemic and brancl]ial hearts and tlie thin- wallt'd genital sac, one wall of whicli Vjears the genital ducts, while on the other the sexual cells arise or the ducts of a separate sexual gland oiien (fig. 392). The gonads of the always dioecious CeiAalopoda are unpaired and lie far back in the visceral sac. The ducts in the female Octopoda (rarely in the males) and in some Decapoda (Oic{opsida) are paired. In Nautilus only the right duct is. functional in either sex, although the left is well developed. Elsewhere there is only the left duct. The oviducts are saccular with glandular walls; independently of them two pairs of glands open to the exterior, the accessory glands and the large nidamental glands. The vas deferens (fig. 302) is more complicated. It has swellings known as seminal vesicle, prostate, and Needham's sac, in which tlie spermatophores are stored. These have such a complicated Fig. :(93.—Spermatophore of Sepia. (From Hatschek, after ]\Iilne Edwards.) (f, dis- charging apparatus ; 6, pacliet of spermatozoa ; r, envelope. structure and show such motions when swollen with water that they were long regarded as piarasitic worms (fig. 393).. .'iM.—Male of Argonanfa nrgn. (After MiiUcr, from Hatschek.) l-i, arms of right side ; , arms of left side ; .;, Iiectocotylisi'd arm. at the left in its sac, at the i-ight protruded. 'i'lu! spermatophores are conveyed to the female by means of more or loss modified (hectocotylised) arms of the male. In a few genera tlie proper tentacle becomes a ' llectocotylus " (fio-. 394).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Hertwig, Richard, 1850-1937; Kingsley, J. S. (John Sterling), 1854-1929. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1902
