SECTS. 145, 146.] OF THE STOMACH AND INTESTINES. 3 15 



muscular coat by a white yielding layer of submucous connective 

 tissue (Tunica nervea of older writers). Of its entire thickness, — 

 which amounts to o # 36"' to o*45'", — o*i"'to o* 12'" belongs to its 

 pavement-epithelium, which presents the same structure as in 

 the oral cavity, with this exception, that the true epithelial 

 plates, perhaps, constitute the half of the whole, and may be 

 stripped off, after short maceration in the dead body, frequently 

 without further preparation, and partly along with the deeper 

 layers, in the form of large white shreds. The proper mucous 

 membrane, on an average o - 3"' in thickness, possesses numerous 

 conical papilla?, 004'" to 0*05'" in length, and consists of ordinary 

 connective tissue, with fine elastic fibres, in which, however, as 

 Brilche and I have found, a large number of smooth muscular 

 fasciculi exist, also more isolated groups of ordinary fat-cells and 

 small racemose mucous glands. 



The oesophagus is moderately well supplied with blood-vessels and 

 lymphatics', the former form simple loops in the papilla, and a 

 moderately wide capillary network at the base, as on the pharynx. 

 Nerves are also observed in considerable numbers in the mucous 

 membrane, with fine fibres o"ooi2'" to croo 15'" in diameter ; still 

 I have not, hitherto, succeeded in following them into the papillae, 

 or recognising divisions or other terminations of them. 



Literati/re. — C. Th. Tourtual, Neue Untcrsuchungen iiber den Bau des 

 Menschlichen Scldund- und Keldkopfes, Leipzig, 1846. 



IV. — Of the Stomach and Intestines. 



§ 145. This portion of the alimentary tract is the most free in 

 its position, and, throughout nearly its whole extent, is supported 

 in the great cavity of the abdomen by special ligaments, named 

 mesenteries. The walls of its several divisions, excepting a small 

 portion of the rectum, are everywhere formed of three coats — 

 namely, a serous, furnished by the peritoneum, a muscular of two 

 or even three layers, and a mucous — and contain in the latter 

 very numerous glandular structures, which are divisible into 

 three groups, racemose mucous glands, tubular glands, and closed 

 follicles. 



§ 146. The peritoneum is considerably thicker and firmer in its 

 outer or parietal layer than in the inner or visceral (in the 

 latter, 0-02'" to 0-03'"' in the former, o - 04'" to o'o6'"); it presents, 

 however, in both parts essentially the same structure, and consists 



