. Comparative anatomy of vertebrates. Anatomy, Comparative; Vertebrates -- Anatomy. UROGENITAL SYSTEM. 329 long in the caecilians (fig. 334) and Amphiuma, saccular in most urodeles, and bifid at the tip in most anura, being even divided into two sacs, connected only at the opening into the cloaca in some species. SAUROPSIDA.—In reptiles and birds, as in all amniotes, the pronephros is rudimentary at all stages and never functions as an excretory organ. The mesonephros takes its place in fcetal life, and in some it continues to function for some time after hatching, but in all it is eventually
. Comparative anatomy of vertebrates. Anatomy, Comparative; Vertebrates -- Anatomy. UROGENITAL SYSTEM. 329 long in the caecilians (fig. 334) and Amphiuma, saccular in most urodeles, and bifid at the tip in most anura, being even divided into two sacs, connected only at the opening into the cloaca in some species. SAUROPSIDA.—In reptiles and birds, as in all amniotes, the pronephros is rudimentary at all stages and never functions as an excretory organ. The mesonephros takes its place in fcetal life, and in some it continues to function for some time after hatching, but in all it is eventually replaced by the metanephros, though its degenerate remains persist in the reptiles (better preserved in the female) forming the so-called 'golden yellow body.' Another part is retained in the male as a part of the efferent ductules of the testes, somewhat as in mammals. The metanephros (fig. 328) never has the ex- tent of the mesonephros of the ichthyopsida, but it is usually restricted to the posterior half of the body cavity, often to the pelvic region. It is usu- ally small and compact (snakes form an exception) or somewhat lobulated, in the snakes the tabulation sometimes being so extensive that the lobules are only connected by the ureter. In the lizards the. 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
