REPRODUCTIVE ORGANS AND GENITAL ARTERIES. 787 



The follicular meshes 1 are close-set in young ova, becoming more open during the 

 later stages of maturation and finally disappearing before oviposition. The nearly ripe 

 ova rupture with the utmost facility, and this may account for certain appearances 

 which have been recorded by Keferstein (1865) and Haller (1895). Keferstein described 

 a large albuminiparous gland (Eiweissdriise) in connection with the ovary, while according 

 to Haller's interpretation {op. cit. p. 199) the ovary is gorged with free yolk in addition 

 to the ova. As I have described above, the vitellus receives its nutriment solely 

 through the vessels of the follicular membrane, and the adventitious occurrence of free 

 yolk can only be ascribed to the rupture of mature or submature ova and is therefore 

 an artefact. 



In the female the short oviduct is closely adherent to the wall of the pericardium, 

 and its ostium abdominale lies behind and closely apposed to the pallio-visceral ligament. 



The male organs of generation have received fresh description on the part of 

 Mr Graham Kerr {op. cit. 1895, p. 671), to whose work I may refer the reader, and also 

 to the explanation of the figures 16 — 19 on my Plate LXXX. The male duct com- 

 prises an external and an internal portion. The latter projects boldly into the perivisceral 

 coelom, where it constitutes a vesicula seminalis of special composition, consisting of two 

 portions separated from one another by a diaphragm perforated near its mesial border 

 (PL LXXX. fig. 17). The ostium abdominale leads into the so-called accessor}/ gland, 

 which contains a complex lumen in which the spermatophore is fabricated, after which it 

 is passed through a very small aperture into the distal thin-walled portion of the seminal 

 vesicle which I will call the antrum. Beyond this point the duct penetrates the integu- 

 ment at the level of the pallial insertion by a narrow neck, and then dilates again to 

 form the so-called Needhamian sac which, as described by Van der Hoeven and by Kerr, 

 is partially subdivided into two cavities by an internal longitudinal septum. The septum 

 presents a free anterior border, in front of which the two halves of the cavity unite, and 

 over which the convoluted spermatophore rests as if upon a saddle (PL LXXX. fig. 18). 



The Needhamian sac is connected with the penis or terminal portion of the vas 

 deferens by a narrow neck surrounded by a sphincter. The penis itself is completely 

 divided by an internal longitudinal septum (described and figured by Kerr) so that it 

 contains two lumina, of which only the right is functional and lodges a spermatophore 

 at maturity, the left lumen ending blindly behind. 



I have no information concerning the manner in which the spermatophore is con- 

 veyed from the penis to its position in the fossa buccalis on the dorsal side of the 

 buccal cone, where it is held by the two most dorsally placed tentacles of the extra- 

 buccal series on each side (PL LXXVII. fig. 6). The transparent membrane or cyst in 

 which the spermatophore is always contained when it occupies this position is probably 

 secreted by some portion of the spadix. 



A mature male will have a spermatophore in the buccal fossa, another in the 

 right penial lumen (which is capable of great distension), and a third in the Need- 

 hamian sac. I do not know how the spermatophore is conveyed to the organ of 



1 The vascular folds of the inner layer of the follicle in the eggs of Sepia, noted in their superficial 

 aspects by Kolliker (1844), were first correctly interpreted and described in detail by Lankester, E. B., 

 " Contributions to the developmental history of the Mollusca." Phil. Trans., Vol. 165, 1875, p. 39. 



w. vi. 103 



