540 DR. DAVY ON THE TORPEDO. 



occasional trials. They also became of rather firmer consistence, and of a darker 

 colour, and perhaps contracted a little in dimensions. The weighing of those first 

 killed was neglected ; of the three which died last, two (males) weighed 510 grains 

 each ; the other (a female) 560 grains. Their stomachs were pretty largely developed, 

 but empty : in the intestine there was a small quantity of yolk remaining, coloured 

 greenish yellow in the inferior part, from the admixture of bile *. 



All these facts seem to show a very slow development, and are in accordance with 

 a long period of utero-gestation ; and I may add, in favour of the same, that the ova 

 in the ovaria of all the three parent fish were very small, the largest of them not ex- 

 ceeding a pea, and the majority of their minute vesicles containing a transparent 

 fluid. 



Other inferences might be drawn from these details, especially in favour of the 

 branchial filaments being absorbent organs, rather than supplying the place of gills 

 (the gills being apparently useless in utero when formed) ; but I am afraid of tres- 

 passing further on the time of the Society on a subject of limited interest. 



In the beginning of this paper, I have alluded to the discrepancy] which exists 

 amongst writers on natural history relative to the mode of generation of the Torpedo. 

 Aristotle always describes this fish as viviparous ; so does Lorenzfni, who wrote in 

 the middle of the seventeenth century. On the contrary, Blumenbach, generally an 

 accurate writer, though he quotes Lorenzini, gives the Torpedo as an example of 

 the oviparous cartilaginous fish, laying a few large eggs, protected by a horny shell. 

 And even Cuvier appears to have fallen into the same error, at least in his Regne 

 Animal he has not corrected it ; and from his general account of the generation of 

 the Rays, both in this work and in his Histoire Naturelle des Poissons, it is to be 

 inferred. It is most probable that analogy and want of confidence in Aristotle and 

 Lorenzini were the cause of this mistake. No doubt, had these able men enjoyed 

 an opportunity of investigating the subject themselves, they would not have failed 

 in ascertaining the truth. Even in Malta, the inquiry is of considerable difficulty, 

 requiring much time and patient waiting, owing to the great rareness of the gravid 

 fish. Some idea of this may be formed, when I mention, that after I had begun the 

 pursuit, more than twelve months elapsed before I could procure a fish with young, 

 though I examined a very large number in hope of finding one, and though I off'ered 

 to pay the fishermen above fifteen times the market price of the fish. 



2. On the Species of Torpedo in the Mediterranean. 



Respecting the number of species of Torpedo found in the Mediterranean, natu- 

 ralists have been much divided in opinion ; some, as Rondelet, followed by Risso, 

 admitting four species ; some, as Bellon, and latterly Ritdolphi_, limiting them to 



* I have never found the stomach of the foetal fish, or of these fish, which were so long without eating, 

 softened or corroded ; a change which I have several times observed in the stomach of the adult fish, killed when 

 there was food in it in process of digestion. 



