. Elements of the comparative anatomy of vertebrates. Anatomy, Comparative. 356 COMPARATIVE AXATOMY Reptiles and Birds.âIn the Sauropsida, as ia the Mammalia, the mesonephros, so far as it is retaiHed in the adult, is entirely separate from the functional excretory apparatus; this consists of a metanephros, entirely wanting in nephrostomes (compare p. 346 and Fig. 273). The metanephros never extends so far along the body-cavity as does the mesonephros; as a rule it has the form of a small compact or lobulated organ, usually situated in the posterior half of the body-cavity, or even entirely co
. Elements of the comparative anatomy of vertebrates. Anatomy, Comparative. 356 COMPARATIVE AXATOMY Reptiles and Birds.âIn the Sauropsida, as ia the Mammalia, the mesonephros, so far as it is retaiHed in the adult, is entirely separate from the functional excretory apparatus; this consists of a metanephros, entirely wanting in nephrostomes (compare p. 346 and Fig. 273). The metanephros never extends so far along the body-cavity as does the mesonephros; as a rule it has the form of a small compact or lobulated organ, usually situated in the posterior half of the body-cavity, or even entirely confined to the pelvic region: it has the latter position, for instance, in most Reptiles. Fig. 2S2.âIJxcretoby Apparatus of Monitor iwlkus. The right kidney is shown in its natural position, while tlie left is turned on its longitudinal axis, so that the ureter and the collecting tubes are visible. The urinary bladder is not represented. N, X, kidneys ; <9(?, collecting tubes which open into the ureter (Ur, Ur"^) â l'r\ aperture of ureter into the cloaca. (Figs. 282, 294 and 295) and all Birds (Fig. 283). The posterior end of the kidney, which is generally narrower than the rest, may even extend under the root of the tail, as in Lacerta, in which region there is a fusion of the organ of either side. Thus, according to the position of the kidneys, the ureters (metanephric ducts) either do not extend freely alono- the. body-cavity, or they may have a longer or shorter free course. The latter is the case, for instance, in Crocodiles, and more especially in Birds (Fig. 283): in the latter the kidneys are closely embedded within the pelvis, and their ventral flattened surface, which is usually divided into three lobes, is. 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 Wiedersheim, Robert, 1848-1923; P
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectanatomycomparative
