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Show 694 DR. E. CRISP O N T H E H I P P O P O T A M U S . [June 27, Kidney and Renal Body.-The kidney in the Elephant and Rhinoceros, like that of the Hippopotamus, is generally lobate; whilst in the Pigs, Tapirs, Peccaries, Hyrax, and members of the equine family it is entire. The renal body in the Hippopotamus is placed further from the kidney than in the other pachyderms, in which it is generally in contact with this organ. In the two Elephants that I examined (Proceedings, 1855, p. 187) the kidneys of the female were lobated, whilst those of the male were entire. Organs of Generation.-All the animals belonging to this family have the generative organs largely developed. In the Pigs the testicles and seminal vesicles are very large. The penis is also large in all, that of the Tapir proportionately larger, I believe, than in any other of the class. The age of this animal precludes a comparative estimate as regards size; and the accidental loss of the organs, as I have said before, prevented m y making an accurate dissection. The tongue, like that of the Wart-Hog (Phacochcerus cethiopicus) is thin and broad at its anterior part. The white papillae I have mentioned are seen in all the Pigs and in the Tapirs; but the form of the basal villi differs from that of the other pachyderms. Larynx and Trachea.-One important difference in the larynx of the Hippopotamus is the pyramidal form of its summit and the great development of the laryngeal muscles. The os hyoides consists of the usual number of bones. The trachea is composed, as I have stated, of twenty-three rings, rather widely separated at the posterior part, as is seen in the dried larynx before the Society. The number of rings in the Horse and Zebra varies from 45 to 52 ; in the Elephant - , Rhinoceros (Owen) 30, Common Hog 28, Wart-Hog 28, Peccaries 33, Tapir (American) 32, and Hyrax 30. So that, judging from this young animal, the Hippopotamus has the smallest number of tracheal rings of any of the pachyderm family. The thyroid glands were perfectly distinct; whereas in some of the pachydermata, as in the Horse, there is a connecting isthmus as in Man. The lungs consist chiefly of two lobes, as in the Seal, Dolphin, and Porpoise; in the Elephant , Rhinoceros (Owen) 5, Tapirs 6, Hogs 6, Peccaries 7, Hyrax 6, and Horse 5. In some of these a very small lobe exists in addition. The lobular divisions I have before described, I believe, are peculiar to the lungs of this quadruped, and are not found in the other pachyderms. In the above description both lobes are spoken of. The heart, with the exception of that of the Elephant, is of a less rounded form in the other members of this group. The opening of the two superior cavae into the right auricle only exists in the Elephant. There are also some important differences in the appendages to the muscular walls of the heart; but want of space prevents me from alluding to them on the present occasion. The most interesting point in connexion with the heart is its bifid character in the newly born animal, as mentioned by Gratiolet in the paper before cited; he says " C'est peut-etre un indice de cette division du coeur qui a ete signals dans la Rhytina, les Duyongs, et les Lamantins." |