ON THE APPENDICES GENITALES (CLASPERS) IN THE SELACHIANS. 79 



employment to be to act as a kind of dilators > of the sexual organs of the female; he imagines 

 them to be introduced until the mouth of the oviduct, whereupon the J/, dilatator dilates the ter- 

 minal part, so that the bore of the oviduct is enlarged, and the male also is enabled to draw the 

 female nearer to itself, in such a manner that he can with his urogenital papilla reach into the 

 cloaca of the female, and there discharge the sperm, which from there more easily may penetrate 

 into the mouths of the oviducts that have been dilated b}- the appendices. 



None of the mentioned authors have been able to found their oj^inions on any observation 

 of the copulation"). Only of late we have one, as it would seem, reliable observation, communicated 

 bv Bolau'), bv which at all events it may be regarded as an established fact that the appendix is 

 really introduced into the genitals of the female. This observation applies to Scylliiiiii stcllarc (cafidus), 

 and is made in the aquarium of the zoological garden in Hamburgh. Before the copulation the male 

 for about a day kept near the female, and pursued her, but it was not observed in what manner he 

 seized her. During the copulation the female is encircled by the male, the latter, as it were, twisting 

 round her cross-wise; only one appendix, it would seem, is introduced at each copulation, and this 

 appendix, judging by the very incomplete .sketch given by Bolau, (I.e. p. 322, fig. 2) must also after 

 the act be somewhat dilated. The copulation itself lasted in two observed cases 20 minutes. Bolau 

 follows Petri with regard to the interpretation of the part played by the appendix on this occasion; 

 but he adds that he is not able to decide, whether the appendix-slit 5) plays a part by the convening 

 of the semen. 



This observation, as far as I know, stands hitherto quite alone; it seems to me to be of no 

 small interest, although it decides nothing with regard to the most important question, whether the 

 appendix really conveys the semen or not. As to this question we are still reduced to draw our in- 

 ferences from the structure of the organ. This structure seems to me to show with complete cer- 

 tainty that at all events the appendix-slit cannot be the duct of the semen; it is situated in 

 such a way, that it is impossible to understand how the sperm should get into it and follow it, as it, 

 as we have seen, is situated dorsally and laterally, sometimes (for inst. in the Skate) quite laterally; 

 the ventrals are not able to perform a movement of such a nature as to make the foremost opening 



M Davy and Agassi?., however, — as also several of the earlier authors (for iust. Rondelet) — have known the 

 following remark in Aristotle, which might be indicative of some observations really having been made in antiquity: 

 "^ slol dk Ttveg ui koifia'/.k^ai ipaai y.ai aui^e/o/JS'^a Twf asla/ib'^ h^ia oTitffi^fsy moTzzp roug zy>a5» (I.e. 5, chap. 5, § 14). In his last 

 communication (1861, p. 500) where Davy rather decidedly declares in favour of construing the appendix as a < penis-, he 

 mentions some circumstances supporting the notion of an .intromission:, derived from Cenlrina , as for inst. that the cloaca 

 of the female is large enough to receive the appendix, tliat it appeared slightly lacerated at its superior commissure*, and 

 that the mouths of the uteri protruded, and were red and blood-filled. Garni an (On the Skates {Kaja^) of the Eastern Coast 

 of the United States. Proc. Boston See. Nat Hist. Vol. XVII, 1S74, p. 171), who, as mentioned, subscribes the opinion of 

 Agassiz, to whom he attributes «the credit of the discovery of the functions of the claspers» , has observed «a fact that adds 

 a little emphasis to his (A.'s) discover}' viz: that in \-irgiiiaI Sharks the hindmost end of the o\-iduct is closed as by a kind of 

 hymen (comp. also Semper: Das Urogenitalsyst. der Plagiost. Arb. Zool.-Zoot. Inst. Wiirzb. vol.2, 1875, p. 279), or provided 

 with a vers' small pore; this pore is round in the species of which the male has tapering claspers , and forms a short, horizontal 

 slit in those where the claspers are flat with rounded ends ; in the species where the appendix has sharp edges and hooks, the 

 hindmost part of the oviduct and the cloaca is very thick and leathery. In virginal Mustchis the oviducts were further- 

 more found stretching along the dorsal side of the cloaca to a point at the middle of the anus; in grown, impregnated 

 specimens they are open, as if an inch or more had been cut off of the end, and the rectum opens in the cloaca between their 

 openings and the outer one. 



2) Uber die Paarung und Fortpflanzung der Scyliium-hxV^w. Zeitschr. f. wiss. Zool. vol. 35. 1881, p. 321. 



3) He wrongly places tlie appendix-sUt on the inner side of the organ, and its partly closed state in Scylliuni seems 

 unknown to him. 



