60 ORIGINAL ARTICLES. 



and Kolliker, and more recently by Max Schultze, are not the true ho- 

 mologues of the electric organs of the torpedo, their position, their 

 structure, and nervous supply, lead me to suppose. Indeed, in so far as 

 this last is concerned, it indicates rather an homological relation with 

 the batteries of the gymnotus, which further research may more fully 

 establish. In alluding to the tail- organs of the skate, I may observe, 

 that in the dog-fish I have found, both in the embryo and the adult, 

 what I conceive to be those organs, in an atrophied condition. They 

 give rise to slight eminences, prolonged from near the vent to the tail ; 

 and, on transverse section, are seen like narrow chinks in the corion, 

 quite separated from the muscles. 



It may occur to some, as it did at first to myself, that the organ 

 which I have described in the skate may represent the " appareil folli- 

 culaire nerveux," noticed by Savi, and by him stated to exist only in the 

 electric rays. I think, however, that this apparatus is clearly an appen- 

 dage of the so-called muciferous tube system ; and, agreeing with the 

 ■views of Leydig, that these appurtenances of the fifth pair are tactile 

 organs, it does not appear that there is any sufficient reason to consider 

 that any homological relation exists between the "appareil follicu- 

 laire nerveux" and the bodies in question. In the electric rays which 

 I have examined, I have not found the body which I regard as the homo- 

 logue of the electric organ ; this fact, indeed, taken along with the con- 

 sideration of the sources from which the nerves of the organ are derived, 

 are the chief points on which the notion rests, that it may be the homo- 

 logue of the electric organ at all; but one also cannot help observing in its 

 position, with reference to the band of muciferous tubes, the lateral line, 

 the temporal orifice, and the posterior branch of the fifth pair, evidence 

 in support of the same idea. In stating, however, that the organ is 

 absent in the electric rays (or, at least, only represented by their bat- 

 teries), I should say that I cannot positively assert this; for the torpedos 

 which have come into my hands have all been partially dissected, and it 

 is possible that the body alluded to may have been Removed. I may 

 beg of naturalists who have opportunities of doing so to determine this 

 point with certainty. 



YIIL— I^OTES ON THE ANATOMY OF THE ALIMENTARY StSTEM! OF THE AxO- 



lotl (Siredon Mexicantjm). By E. Perceval Wright, A. M. Dub. 

 and Oxon., M. B., F. L. S., Lecturer on Zoology, University of 

 Dublin (with Plate II.). 



The earlier investigators of the anatomy of the axolotl appear to have 

 regarded it as a larval form. This, some of them, as Rusconi, did, judg- 

 ing merely from its external appearance ; others, as Cuvier, even after a 

 somewhat minute investigation into its anatomy. 



Hunter, it is true, was convinced that they were adult forms, and 

 merited but little the censures passed upon him by Busconi, who, from 

 constantly studying the salamanders and their metamorphosis, dogmati- 



