141 



above or within the valve that separates it from the outer cavity. 

 The lower or ventral margin of the valve is grooved, and the groove 

 is continued on into that of the penis* 



** The peritoneal canals opened externally on two small papillae 

 placed one on either side the root of the penis; they also commu- 

 nicated at about a line distant from their external aperture, with 

 the cavernous structure of the penis. From the minute size of 

 these orifices, which barely allow of the passage of an eye-probe, 

 and their disposition on a papilla, equivalent to a valvular structure 

 on pressure from without, it is difficult to imagine that any water 

 can be admitted from without into the peritoneal cavity ; yet M. 

 GeofFroy-Saint-Hilaire hazards the hypothesis that water is so ad- 

 mitted by means of a similar mechanism to that by which air passes 

 through the trachea into the pulmonary cavity, the peritoneum being 

 thus rendered an accessory organ of respiration. ' Le voila,' he 

 says, (speaking of the Crocodile, in bis ' Description des Reptiles de 

 l'Egypte,' page 237,) * veritable amphibie, dans ce sens qu'il est 

 animal aerien par sa poitrine et animal aquatique par une modifi- 

 cation de l'etat de son abdomen.' Yet, notwithstanding the op- 

 portunities this author enjoyed of examining the Crocodile under 

 circumstances most favourable for such an observation, he does 

 not appear to have ever detected water in the abdominal ca- 

 vity j nor any peculiarity in the contents of that cavity, which 

 would give support to his hypothesis. 



f! The appearances in this dissection precisely accorded with the 

 description given by M. GeofFroy-Saint-Hilaire of the diaphragm 

 and its connection with the liver in the Egyptian Crocodile. 



" The spleen lies on the right side of the abdomen, beneath the 

 right lobe of the liver ; it was two inches and a half in length, and 

 about half an inch across at the broader part. It is entirely sur- 

 rounded by peritoneum, and lies very loose, being connected only 

 by a very small process of that membrane accompanying the vessels 

 to the upper part of the duodenal fold. It is here, therefore, that 

 the structure most favourable for the detection of an excretory duct 

 obtains, if the spleen really possessed such an appendage, its pas- 

 sage from the gland, in that case, being limited to a very small space, 

 and this space circumscribed by a diaphanous membrane. But it 

 was easy to see that this membrane contained only a small artery de- 

 rived from the branch that supplied the pancreas, (having none 

 analogous to the vasa brevia in man) ; a vein of disproportionate 

 size, which terminated in the venaportce; two small nervous fila- 

 ments ; and a delicate connecting tissue. 



** There is a lacteal gland at the root of the mesentery as large 

 as the spleen." 



Mr. Owen stated his intention of bringing before the Committee 

 at an early meeting the remaining portion of his notes on this sub- 

 ject. 



Mr. Owen also read to the Meeting the following Notes on the 

 Anatomy of the Nine-banded Armadillo, (Dasypus Peba, Desm.) 



