. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 296 REPTILIA. length of the intestine, and corresponds to the duodenum of birds. The other part is of smaller diameter, and has thicker walls, en- closing between the mucous and muscular tunics a layer of glandular substance, re- sembling a greyish, semitransparent pulp. The lining membrane of the intestine which covers this glandular layer is disposed in longitudinal zig-zags, connected together by little folds that pass from one to another, so as to constitute a fine net-work. These zig-zags are replaced by delicate vi
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. 296 REPTILIA. length of the intestine, and corresponds to the duodenum of birds. The other part is of smaller diameter, and has thicker walls, en- closing between the mucous and muscular tunics a layer of glandular substance, re- sembling a greyish, semitransparent pulp. The lining membrane of the intestine which covers this glandular layer is disposed in longitudinal zig-zags, connected together by little folds that pass from one to another, so as to constitute a fine net-work. These zig-zags are replaced by delicate villosities in the first portion of the small intestine, where the glandular layer is not perceptible ; and towards its termination in the large intestine, they become reduced to undulating folds, rarely joined together by transverse plicae. In the larger intestine itself, they are con- verted into irregular projections, which form a sort of villous surface. In the other families of saurian reptiles, the form and structure of the stomach may be referred to the common type which we have already seen in the Chelonians. The oesophagus is wide, with very extensive walls, as is indicated by the longitudinal folds of its lining membrane; it is generally of the same diameter with the stomach, which latter forms a cylindrical or conical bowel, directed from before backwards, and generally bent a little towards the right near its termination, so that we may distinguish a pyloric portion extending from the bend to the pylorus, the length of which is very variable, and which is distinguishable from the rest of the stomach by the greater thickness of its coat. At the entrance of the duodenum there is a promi- nent muscular ring, serving the office of a pyloric valve. The great curvature, which is generally more dilated, is sometimes, though rarely, prolonged into a small cul-de-sac (Monitor of the Nile}. The small intestine of the Laccrtidcs is short and sometimes very capacious in the firs
Size: 798px × 3133px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, booksubjectanatomy, booksubjectphysiology, booksubjectzoology
