70 Prof. J. Van der Hoeven on the Anatomy 



period of sexual orgasm, I found the sperm ophore-sac, forcibly 

 distended by its contents, to occupy the entire space between the 

 anus and the base of the penis near the right anterior gill, whilst 

 a spermophore filled the penis and came partially into view at its 

 aperture (PI. VI. fig. 1). 



The parts found by me in Nautilus present on the whole the 

 same type which we remark in the male sexual organs of the 

 dibranchiate Cephalopods. The canal which I have indicated as 

 vas deferens corresponds at its uppermost wider part, furnished 

 with thick walls, with the part that Cuvier designates as vesicula 

 seminalis in Octopus. The saccule in which this canal terminates 

 may be compared with the part which this illustrious anatomist 

 and others after him have regarded as a prostata, although with 

 greater justice it may be taken for a vesicula seminalis. The 

 glandular tissue which surrounds and covers the vas deferens 

 seems to be wanting in the rest of the Cephalopods. In the 

 smallness of the spermophore-sac, and in some other particulars, 

 Octopus approaches nearer to Nautilus than do Sepia and Loligo ; 

 in the spermophores also, a closer affinity of Nautilus with Octopus 

 may be remarked than with the ten-armed Cephalopods. 



In the upper end of the efferent tube (that part which corre- 

 sponds to the vesicula spermatica of authors), I found spermo- 

 phores still imperfect and very soft ; they were more developed 

 in the small saccule in which the tube terminates ; but a greater 

 firmness and a definite convolution in spiral turns are seen first 

 in the sac in which they are collected under the penis. 



From this Needhamian sac, which beyond doubt is contractile, 

 the spermophores are brought into the canal of the penis and 

 from thence into the gill-sac. From thence they arrive, whether 

 through the funnel or along the free margin of the mantle, at 

 the different parts above, which as tentaculiferous slips surround 

 the muscular bulb of the mouth. 



That the spermophores tarry there for a time, before they 

 leave the aperture of the shell to reach the shell of the female 

 Nautilus, appears to me most likely. In three specimens I 

 have found them there, and in all at the same part. This 

 was on the dorsal surface, under the hood, and between the 

 two first and smaller tentacles of the two processus labiales, 

 those of the left side surrounding them like two fingers, whilst 

 a cavity was, as it were, impressed for them at the base of the 

 right tentaculiferous lobe by a bladder which enclosed the spermo- 

 phore. For here the spermophores do not lie uncovered; on 

 the contrary, they are enclosed in a round, brown vesicle, which is 

 about 18 millimeters long and 15 mm. broad, and of which the 

 walls consist of three or four structureless membranes lying 

 upon one another. 



