18"6.] CJECUM 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 coecum capping the end of the sacculated one an- 

 teriorly. 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 iu 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 2h 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 epigastric 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 am 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 I foot 

 10 inches. 



The liver is comparatively simple. The gall-bladder is pyriform, 

 situated in a cystic fossa, not reaching ihe 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. 



