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Show 296 LIEUT.-COL. H. H. GODWIN-AUSTEN ON [Apr. 20, against the thin membrane beneath (If b) ; and following this down, was found to be the basal end of the spermatophore, with the peculiar cervicorn processes at the base, in situ where developed. On opening the membranous sac, it was found to consist of one continuous' thread coiled down on itself (fig. 3), and pressed closely too-ether, and was in such good preservation as to be easily unravelled. I drew out and measured a portion -jL inch in length, and found it to contain 15*1 inches; the whole length of this part being *55 inch in length, would give nearly 7 feet for the total contents of the sac. It is, in fact, a spermatic thread of hardened spermatozoa, poured out from the vas deferens 1. On further examining the part near c, this cylindrical portion was found to end in a conical cap, which again gave off a thin rod, which bending sharply back, is evidently in communication with the extension of the vas deferens towards d. Behind the junction of this last is a short gland rounded at the end (e), which contained some very microscopic transparent crystalline bodies of oval form (fig. 2, a). This is the Kalksack mentioned above, and secretes the material for the formation of the spermatophore. This spermatophore, which is an organ of a very complicated and curious form, may be thus described:-The basal or anterior end consists of a chitinous strap about 0*4 inch long, with the sides more or less turned over, forming a sort of trough or long spout, which, after it has passed into the spermatheca of the other individual, will be found opening into the lower part of the oviduct. At the other end the sides at last meet and form a tube; it then thickens and widens, giving off several strong cervicorn or more or less branched processes, which are directed backwards; they serve, I think, to aid in the expulsion of the spermatophore from the penis, and, when once within the spermatheca or vagina, serve as holding-hooks to prevent its withdrawal. The part above this consists of a very long thin membranous bag 0*4 inch long, terminating in a hard conical cap, from which proceeds a thin rod, which is found to extend to the hard rounded apex of the spermatic sac, where it bends over or ends in a few separate filaments within the tube of the vas deferens. In one specimen of this species (gigas) no less than seven perfect spermatophores were counted, closely packed together side by side within the spermatheca. (Van Beneden observed two in a Parmacella, Ann. Sci. Nat. 1857, p. 371.) It would appear that in these creatures even one act of copulation would fertilize for a very considerable period ; for it would be some time before the contents of a spermatophore became exhausted. This organ, as situated in the penis, presents the character of a perfect spring (vide Plate X X V I . figs. 2, 3) ; and it can be imagined that when it enters the wider and very elastic sac of the spermatheca, and is then gradually released, it will tend to become quite straight, and that, the recurved processes holding it at one point, the longer portion will bend round to the long axis of the sac, bringing the end 1 This thread is similarly described by M . Baudelot, I. c. p. 165, in his description of the capreolus of Arion rufus. |
