| OCR Text |
Show 1876.] CECUM COLI OF THE CAPYBARA. 23 longitudinal muscular coat is strongly marked, covering it perfectly uniformly. The ileo-caecal valve is linear and longitudinal; it projects a short distance into the sacculated caecum from above as a tube with slightly turned lips, of which the inferior is a little the longer and larger. There are some thickened gland-patches in the sacculated caecum, and a large one in the colon, at the margin of the sphincter which is towards the continuation of the large intestine; three or four others are situated irregularly in the walls of the true caecum. The disposition of the colon is peculiar and interesting. The accompanying sketch (fig. 2, p. 22) will explain it best. It was taken from the view obtained of them as the animal lay on its back. As is well known, the large intestine commences in the left hypochondriac region, the true cseeum capping the end of the sacculated one anteriorly. The gut then, with a curve to the right, runs back to the hypogastric region, where, with a reversed figure-of-eight twist, it gets into the normal position of the ascending colon. It so reaches the right hypochondriac region, and then commences to form, in the transverse colon, coils very similar to, though on a smaller scale than those in Indris among the Lemurs and in the Artiodactylate Ungulata, the much-developed loop being twisted on itself to the left side. After reaching the left hypochondrium the descending colon continues straight to the sigmoid flexure, which is strongly developed, and thence to the rectum. The sacculated caecum being bound to the first part of the colon by bands of equal length (about 2 | inches), follows the course of that canal, and is therefore doubled on itself, not, as Prof. Owen remarks, occupying the posterior half of the abdomen, but running forwards towards the diaphragm, above the colon, till its caput arrives in the right hypochondriac and epigastrie regions, where the ruminant-like coil above referred to is strongly bound to it on its under or ventral surface. Neither in Cavia, Dolichotis, Capromys, nor in any of the allied forms with which I ara acquainted, does the strong sigmoid curve of the large intestine, at the commencement of the sacculated caecum, develop into a true secondary caecum in the manner that it does in the Capybara. Whilst on the subject of the viscera of the Capybara, the following measurements of those of an adult male will not be out of place- small intestine 21 feet, large intestine 6 feet 7 inches, caecum 1 foot 10 inches. The liver is comparatively simple. The gall-bladder is pyriform, situated in a cystic fossa, not reaching the free margin of the gland. The right central lobe is slightly more bulky than the left lateral, which is more than twice the size of the left central, which, again, is somewhat larger than the caudate. The spigelian lobe is minute, and bifid as in so many Rodents. |
