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XXIV. Observations on the Torpedo, with an account of some additional Eocperirnents 

 on its Electricity. By John Davy, M.D, F.R.S. Assistant Inspector of Army 

 Hospitals. Communicated hy Sir James M'^Grigor, Bart. F.R.S. Director Ge- 

 neral of the Army Medical Department. 



Received May 15, — Read June 19, 1834. 



1 . On the Foetal Development of the Torpedo. 



1 HE accounts we possess by different naturalists of the mode of generation of this 

 fish are so discordant and perplexing", that I have been induced to investigate the 

 subject afresh, and I now propose to submit to the Society the results of my obser- 

 vations. 



It may be advisable to premise a few particulars respecting the generative organs 

 of the Torpedo. The female, like those Rays and Squali which are considered ovo- 

 viviparous, has two ovaria, a common oviduct and two uterine cavities. The ovaria, 

 one on each side of the spine, are attached to and enveloped in a fold of the perito- 

 naeum, just above the liver and a very little below the common infundibulum, or 

 opening of the oviduct. The oviduct passes round on each side under the liver, and 

 ends in an enlargement, one over each kidney, which from its function may be called 

 a uterine cavity, formed, like the duct itself, of a villous inner membrane and of a 

 peritonseal outer coat, connected together by loose filamentous tissue, and opening 

 into the lower part of the intestine or cloaca by a common mouth, a little posterior 

 to the minute papilla, the termination of the ureters. In the oviduct, just above its 

 enlargement into the uterine cavity, there is only a slight trace of a glandular struc- 

 ture, in which respect the Torpedo appears equally to differ from the different spe- 

 cies of Squalus and of Ray ; all those which I have examined of either genus being 

 possessed of a large glandular body in the situation mentioned. 



The male generative organs consist of two firm oval testes, occupying the same 

 situation as the ovaria in the female, and not very different in appearance ; of vasa 

 deferentia without vesiculse seminales ; and of a papilla in the cloaca, the common 

 termination of the seminal and urinary passages, near the verge of the intestine. 



Like the Squali and Rays in general, the male Torpedo is provided with two ap- 

 pendices, one on each side of the anus, composed of articulated bones, of muscles, 

 of cartilages, and a glandular structure. 



The eggs of the Torpedo I have never found in the oviduct in their passage, but only 

 in the ovaria, or attached to the ovaria, or in the uterine cavities. When mature and 



