162 



Prof. Huxley. Epipubis of the Dog and Fox. [Feb. 5, 



is the true one, not disproving the presence of nitrogen ; or else the 

 atmosphere which the comet meets is hydrogen and contains no free 

 nitrogen. 



II. " On the Epipubis in the Dog and Fox.'" By T. H. Huxley, 

 Sec. U.S. Received January 30, 1880. 



In 1871* I gave a brief description of a structure which I had ob- 

 served in the dog, in the following terms : — 



" In the myology of the dog, the insertion of the tendon of the 

 external oblique muscle of the abdomen presents some interesting pecu- 

 liarities. The outer and posterior fibres of this muscle end in a fascia, 

 which is partly continued over the thigh as fascia lata, and partly forms 

 an 1 arch (Poupart's ligament) over the femoral vessels; by its inuer 

 end it is inserted into the outer side of a triangular fibro-cartilage, the 

 broad base of which is attached to the anterior margin of the pubis, 

 between its spine and the symphysis, while its apex lies in the abdo- 

 minal parietes. The internal tendon of the external oblique unites 

 with the tendon of the internal oblique to form the inner pillar of the 

 abdominal ring, and is inserted into the inner side of the triangular 

 fibro-cartilage. The pectineus is attached to the ventral face of the 

 cartilage ; the outer part of the tendon of the rectus into its dorsal 

 face ; but the chief part of that tendon is inserted into the pubis 

 behind it. This fibro-cartilage appears to represent the marsupial bone, 

 or cartilage, of the Monotremes and Marsupials." 



The only reference to this statement which I have met with is by 

 Professor Macalister, in his "Introduction to the Systematic Zoology 

 and the Morphology of Vertebrate Animals " (1878), p. 265 : — 



" Professor Huxley describes a fibro- cartilaginous ' marsupial ' above 

 the pubis, from whose anterior surface the pectineus arises. I have 

 failed to satisfy myself of its existence as a constant structure in many 

 dogs, in the common and Bengal foxes, in the dingo, jackal, Ganis 

 pallipes, and wolf." 



The wording of this passage does not make it quite clear whether the 

 writer has not found the structure in any case, but does not mean to deny 

 that it may occur occasionally in the various Canidce he mentions ; or 

 whether he has found it occasionally, but not constantly, in all or some 

 of them. 



Under these circumstances, it may be desirable to publish the fact 

 that, having recently dissected, for purposes of comparison, a male and 

 female fox and a male and female dog, I have not had the slightest diffi- 

 culty in demonstrating the existence of the structure which I described 



* " Manual of the Anatomy of Vertebrated Animals," p. 417. 



