ON TIN'. APPENDICES GENITAI.ES (CLASPERS) IN THE SELACHIANS. 



adherents, but the notion that they are real penes, i.e. organs conveying the semen, seems never to 

 have been fully superseded by it; Blainville advocates this opinion 1 ), and later we find it in Mayer 2 ), 

 in LeydigJ), Stannius-t), Steenstrups), L. Agassiz 6 ), Davy/), and (partly) Giiuther 8 ); this 

 opinion, after all, is perhaps to this day the most widely spread; it is also rather obvious, and analo- 

 gies from other groups of animals present themselves, as it were, spontaneously 9). This interpretation 

 of the appendages as the direct conveyers of the semen, however, meets with difficulties, which partly 

 have been correctly seen by several authors; some of those then have adhered to the opinion that 

 they are introduced into the cloaca of the female, but only to be more indirectly subserving the copu- 

 lation. Thus Geoffroy St. Hilaire 10 ) characterizes them as clitores, and Petri 11 ) thinks their chief 



■I I.e. p. 126. Blainville promises a treatise on la structure et les usages de ces appendices dans les raies et les 

 squales , in which he even thinks to have found a connection with the sexual organs proper, what he had not been able to 

 do in le S quale pelerin . 



2 ) TJber die Bedeutung der fussformigen Anhange bei Rochen und Hayen , und ihr Wiedervorkommen bei niederen 

 Thieren. Frorieps Notizen aus dem Geb. der Natur- und Heilkunde, vol.40, 1834, p. 273. Mayer supposes that these limbs 

 by the Mitscnli adductores are brought to the cloaca, receive the semen into the appendix-slit, and convey it on to the terminal 

 part, the opened leaves of which wie ein Blumenkelch embrace the cloaca of the female; further he imagines that the 

 copulating animals wahrscheinlich von einajider abgewendet sich befiuden (Petri 1. c. p. 291 reHders the description by M., 

 but in more respects incorrectly). 



;) 1. c. p. 86. Hie sogen anil ten Haftorgane erinnern in ihrer gewundenen, rinnenformigeu Gestalt sehr an die ausseren 

 Begattungsorgane maneher Krebse und ich glaube, dass sie ebenso wie diese zum Uberpflauzen des Samens nach den weib- 

 lichen Geschlechtstheilen dienen, wobei dann das Sekret der oben beschriebenen Driise eine vielleicht die Samenmasse ein- 

 hullende oder schiitzende Rolle spielt . 



4) Handbuch der Anatomie der Wirbelthiere, 2 Aufl., 1S54, I, p. 278, note 5. 



5) Hectocotyldannelsen hos Octopodslaegterne Argonauta og Tremoctopus. Kgl. D. Vid. Selsk. Skrifter, 1S56, p. 26. 

 «I think, however, .... the analogon to be as obvious, which is found in so many males among the decapod Crustacea, in 

 which a pair of the abdominal limbs are formed as more or less complete tubes, or the analogon, seen in the male Rays and 

 Sharks, where the ventrals, that is to say, active organs of motion, have one side transformed into large ducts of the semen. 



6 ) 1) Proceedings of the Boston Society of Nat. Hist. Vol. VI, 1856—59, p. 377. 2) Ibid. Vol. XIV, 1871, p. 339. In 

 the first-mentioned place is only found a report of some observations by Agassiz occasioned by a lecture on the egg-devel- 

 opment in Rays; he thinks the claspers • of the Rays to be real copulatorv organs, supposing them to be turned forward 

 and upward, by which turning an opening in them (the larger basal opening of the appendix-slit?) is brought up to the 

 spermatic ducts ; it is supposed that they may easily be introduced into the oviduct even to the shell-gland. In the later 

 communication (2) this is more particularly worked out: One raj' of each posterior fin is capable of erection and rotation, 

 and is covered with erectile tissue, far too delicate to allow it to be used as a clasper around a body covered w-ith sharp 

 rough spines. In the act these two organs are rotated inward and forward, bringing the furrows on their inner surface into 

 parallel contact, and in apposition with the testes. Being then introduced into the body of the female, their extremities 

 diverge in the two oviducts, and the glans being uncovered exposes a sharp cutting instrument, which would injure the 

 organs of the female if she resisted ; the male has her, therefore, in complete subjection, and has been observed to strike and 

 wound her with this spine. What was formerly supposed to be the penis is too small, and of insufficient length to accom- 

 plish fecundation (viz. the urogenital papilla). The penis consists of the two long flexible finger-like fins, furnished with two 

 projectile spinous appendages as in vipers. (In Ckimcera the surfaces of the organs are also spinous, as in snakes). The two 

 spines found in cartilaginous fishes are homologous with the OS penis of mammals. In men this bony part has disappeared, 

 and we have only the soft spongy portions of the organ remaining; the quivering of the legs during connection seems the 

 echo, as it were, of the sensitiveness of the flexible posterior limbs of the skates 1!). As the thought of a comparison with the 

 Snakes cannot be said to have been exactly new at that time, so it is also the case with the homology with the os penis ; it is 

 already found in Ray (Willughby: De Hist. Pise. etc. 1686, p. 77). Gar man, 1. c. p. 199—200, subscribes the opinion of Agassiz. 



1) Already I.e. 1839, p. 149; more decidedly in: Fragmentary Notes on the Generative Organs of some Cartilaginous 

 Fishes (Trans. Roy. Soc. Edinb. 1S61; vol.22, p. 500). 



1 Introduction etc. p. 167. Gunther also supposes that the two appendices by being put together may form one 

 canal; he thinks it to be possible that the appendix-slit leads as well the secretion of the glandular bag as the sperm. 



9) Besides to the palps of the Araneina, the thought will easily be led to the limbs that in the Crustacea, especially 

 1,11 Decapoda, have been developed for serving the copulation; not only Leydig and Steenstrup, as has been shown by 

 the above quotations, but also Mayer have thought of these; several other analogies indicated by Mayer are rather distant 

 a if they be not all so distant as those, attributed to M. by Petri: the thumb-swellings in the frogs, the spur of the 

 Ornithorhynchus — which analogies I have not at all been able to find mentioned in M.I. 

 According to Petri; I have not been able to find the essay in question. 

 ") '■<'■ P- 330. The secondary function, which Petri (in accordance with Bloch) ascribes to them: to serve as an 

 organ of motion making the males more mobile than the females - especially in the Rays — may surely, to say the least 

 of it, be characterized as problematic. 



