302 Zoological Colledions, Vertebrnta. 



into the circumstance related by Sir Everard Home, of there being air in 

 the interior of the sexual organs of the female. Directed by M. St Hildre, 

 Dr Martin de St Ange examined whether or not there were peritoneal 

 canals, as in the crocodile and turtle. He had not searched long before 

 he found them open at the fundus of the uterus, on the inside of the 

 uterine necks of the two ad-uterums ; these canals opened into the abdomen, 

 near, ami on the inner side of the roots of each ad-uterum. 



Thus, says St Hilaire, I have discovered tubes carrying air into the 

 abdomen ; and, which is of great importance, upon the ovaries, I have 

 seen the ovaries formed like those of birds ; ovula in small number, but 

 large ; ovula of all sizes, and some larger and irregular on the surface, like 

 the ovulum of the common mammifera, when it has come to its degree of 

 maturity in the uterus. I have also found the ad-uterums of the body of 

 the central uterus ; they have a black membrane, which lines the interior. 

 1 have seen a bag near, and a little to the inside of the margin of the anus, 

 which is quite similar to that singular bag which Fabricius ab Aquapendente 

 discovered in birds, and which has been called Bursa Fahricii. From its 

 size, it would be expected to have an important use. It is nothing but a 

 repetition of the preputial bursa of the penis of the male. It is true that 

 it presents this extraordinary circumstance, that it is large even when the 

 clitoris is extremely small. 



Now, the author continues, the use of the marsupial bones is discovered ; 

 they favour the entrance of the air towards the anal opening, by enlarging 

 the capacity of the abdomen. The gap made by these bones, performing 

 in this place the office of a sternum, causes the air to penetrate into the 

 sexual organs, and into the abdomen, by means of its own elasticity. 



It might be inferred, that, as in the turtle and the crocodile, the peritoneal 

 canal should be met with in both sexes ; but M. St Hilaire, assisted by 

 M. Martin de St Ange, could not discover them in a male which died some 



time after the female Bull, des Sci. Nat. Nov. 1830. j 



\o 



On the changes of Shape which the Cranium of the Otter undergoes by Age. 

 By M. Be j ihold — The differences between the crania of the young and 

 adult otter are very striking, particularly with regard to the frontal bones. 

 In the young animal, the frontal bones are broad and extensive, but as age 

 advances, they become narrow ; and as the frontal bones form the cavity of 

 the olfactory lobes, it follows that the size of these must diminish with age. 

 In the young animal, the parietal bones give a rounded form to the cranium ; 

 but in the adult, the cranium becomes more angular and broader at its base; 

 the sagittal suture rises in the form of a crest ; the lambdoidal suture 

 becomes equally prominent, and projects above the occipital, the dimensions 

 of which increase with age ; the occipital hole, which is sunk in the young 

 animal, has its margins more projecting as age advances. The ethmoid is 

 almost as much developed in the young as in the old animal, as are also the 

 nasal bones. The malar bones are considerably separated from the head, 

 and are prolonged as age advances. 



Generally speaking, the cranium of the adult animal has the greatest 

 analogy to that of the seal, and the cranium of the young animal to that of 

 the polecat — Ibid. 



Remarks on M. PrevosVs Observations on the Circulation of the Foetus of 

 Ruminants. By M. Raspail. — Some years ago, M. Prevost announced 

 that the globules of the blood of the foetus differ in diameter from those 

 of the mother ; whence he concluded, that in the mammifera, there was no 

 direct communication between the vascular systems of the foetus and 

 mother. 



M. Breschet and I have verified the observations of M. Prevost, having 

 found the globules of the blood of the foetus of a dog three tipaes larger 



