. Comparative anatomy of vertebrates. Anatomy, Comparative; Vertebrates -- Anatomy. FIG. 231.—Spiral valve of Raia, after Mayer. one or two blind pouches or caeca at their junction or by a circular fold or a pair of internal folds of the lining, constituting an ileo-colic (ileo-caecal) valve, both valve and caeca coexisting in many cases. Both large and small intestines may be subdivided, chiefly by differ- ences in their walls. Thus in the small intestine there may be recognized in different groups a jejunum, a spiral valve region and an ileum, while the large intestine may furnish a colon, a
. Comparative anatomy of vertebrates. Anatomy, Comparative; Vertebrates -- Anatomy. FIG. 231.—Spiral valve of Raia, after Mayer. one or two blind pouches or caeca at their junction or by a circular fold or a pair of internal folds of the lining, constituting an ileo-colic (ileo-caecal) valve, both valve and caeca coexisting in many cases. Both large and small intestines may be subdivided, chiefly by differ- ences in their walls. Thus in the small intestine there may be recognized in different groups a jejunum, a spiral valve region and an ileum, while the large intestine may furnish a colon, a rectum and a cloaca. In the cyclostomes but two regions occur, the intestine and the rectum, differentiated ex- ternally by the larger size of the latter. In the petromyzonts there is an internal fold of the in- FIG. 232.—Diagram . of spiral valve of Carcha- tcstme which pursues a slightly spiral course, constituting a spiral valve, a structure which reaches its highest development in the elasmobranchs. In the elasmobranchs the intestine is nearly straight, but its dif- ferentiation has proceeded farther. At the junction of small and large intestine is a dorsal blind sac, the rectal gland. Its function is un-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Kingsley, J. S. (John Sterling), 1854-1929. Philadelphia, P. Blakiston's son & co.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1912
