562 DR. J. MTIBIB ON THE ANATOMY OP THE SEA-LION. 



d. Intestines. — The small intestines have a nearly uniform calibre throughout their 

 entire course ; the average diameter is three quarters of an inch. From the pyloric 

 extremity of the stomach to the ileo-ceecal valve they have a length of 60 feet 

 2^ inches. 



Excepting the curve of the gut as it passes round the head of the pancreas, which 

 may be arbitrarily termed the duodenum, there is no definite change in the character 

 of the internal mucous membrane sufficient to limit the above as it passes on to the so- 

 called jejunum. In like mannei', excepting greater frequency of Peyer's patches, no 

 line of demarcation exists between the jejunum and ileum. No vahailse conniventes 

 are present. The mucous lining of the whole of the small intestines ordinarily appears 

 to the eye as smooth; but looked at more closely, and especially under water, the 

 membrane is seen to be of a velvety or minutely villous character. The villi are 

 arranged in transverse linear folds of a very delicate kind. 



At the distance of 22 feet from the pyloric orifice the first Peyer's patch is found. 

 It is 3 inches long and about 0-7 inch broad. Fourteen feet further on another patch 

 of Peyer's glands is met with, which measures 7 inches in length, with a rather greater 

 breadth than the first patch. The third agminated gland is 5 feet 10 inches apart from 

 the second, and like it is broadish, but 5^ inches long. A very considerable interspace 

 then follows, apparently free from these glands. Eleven inches backwards from the 

 ileo-ceecal valve there terminates an extraordinary long and continuous Peyer's gland. 

 This enormous gland, or lengthened group of Peyer's vesicles, measures 4 feet 8 inches 

 from the one extremity to the other. It varies in breadth from 0'5 to 0'8 inch, and in 

 some places the vesicles or pits are more distinct than in others, but throughout its 

 whole extent is well marked. 



The caput caecum coli is a simple, wide, cylindroid diverticulum, half an inch long. 



The great intestine has few flexures ; and its walls are remarkably free from saccula- 

 tions. From the ileo-csecal valve to the anus it measures 59^ inches, including caecum. 

 The diameter of the greater part of its course is Ij inch, widening near the rectum 

 to IJ inch. Mucous, muscular, and serous coats are each and all of considerable thick- 

 ness. As may be inferred from the absence of sacculations, the longitudinal muscular 

 fibres are not segregated in bands, but form a more or less uniformly distributed outer 

 coat, thickest at the rectal portion, and terminating with the circular fibres in a large 

 sphincter ani internus. The mucous folds are irregular slight elevations and shallow 

 depressions, which only acquire a pronounced character at the lower part of the gut. 

 The surface throughout has a minutely granulated appearance. 



From what has been said it follows that the total length of the alimentary 

 tract (that is, from the mouth to anus) is approximately equivalent to 69 feet : of 

 this the oesophagus counts 22^ inches, the stomach 21 inches, and the intestinal tube 

 65 feet 2 inches. 



