The discovery of the nature of the spleen : from an investigation of the lateral homologies of the liver, stomach, and intestinal canal / by Henry R. Silvester.

Silvester, Henry R. (Henry Robert), 1829-1908.

Date:: 1870

Credit: The discovery of the nature of the spleen : from an investigation of the lateral homologies of the liver, stomach, and intestinal canal / by Henry R. Silvester. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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$numerous internal transverse folds; the hippopotamus has two cardiac pouches opening widely into the rest of the stomach. In the tapii- and hyrax this organ forms two cavities. In the pig the stomach resembles that of man, though the cardiac end is more projecting, and a consider- able extent of the lining membrane, near the oesophageal opening, is covered with thick epitheHum. In the peccary still more of the cardiac portion is lined with a dense epithelium. In the solipeds the stomach is rounder, the oesophageal and pyloric openings are near to each other, and the cardiac portion is lined by a thick epithelium, which tei-minates in a dentated margin. In the rodentia the stomach is often marked off by a cardiac, and a pyloric portion, often indicated by an external constriction. Marsupials have a simple, somewhat elongated stomach. In the kangaroo the stomach is as long as the body, and the middle portion is sacculated, and marked by three longitudinal folds. It has three compartments, two being cardiac pouches, and also three rows of large ciypts, along the bands. Among cetacea the dugong has this organ elongated, ^ind marked off into a cardiac and a pyloric portion by a con- striction, from near which two blind pouches proceed. In Birds.—The digestive,canal is usually complex ; the oesophagus being more or less dilated near its low^er end to form the crop to which s\iccecds the proventriculus, or proper secreting stomach, and beyond this is a third cavity, forming the gizzard. The crop is most developed in the gi-ain-eating gallinacea, forming a dependent bag connected with one side of the oesophagus, as in the fowl, or as in pigeons, consisting even of two lateral oval sacs. The second, or lower oesophagus, has no constricted cardiac orifice. The proventriculus, the true glandular stomacli, varies in form, being sometimes wide and straight, some- times round. The gizzard is the third, or muscular stomach of birds. A pyloric valve usually exists in birds. In Reptiles.—The alimentaiy canal in this class is more simple than in bu-ds, to which, however, it approaches more nearly than to that of fish. The oesophagus, as in birds, joins the stomach without any constriction or car- diac orifice. In the large saurians, the first part of the stomach has the foi-m and structure of the gizzard. The pyloric part is more decidedly glandular, and corresponds$