. Outlines of zoology. Zoology. 6l2 BIRDS. cloaca. The predominance of urates in the active birds, with high oxidation and blood very rich in red corpuscles should be borne in mind when the physiological relations of uric acid to metabolism are studied. In front of each kidney, at the ba,se of the iliac vein, there lies a supra- renal body. Reproductive System. The testes lie in front of the kidneys. They increase in size before the breeding season. The sexual period in birds is often narrowly limited. The spermatozoa pass from the testis into a vas deferens, which Ues to the outside of the co
. Outlines of zoology. Zoology. 6l2 BIRDS. cloaca. The predominance of urates in the active birds, with high oxidation and blood very rich in red corpuscles should be borne in mind when the physiological relations of uric acid to metabolism are studied. In front of each kidney, at the ba,se of the iliac vein, there lies a supra- renal body. Reproductive System. The testes lie in front of the kidneys. They increase in size before the breeding season. The sexual period in birds is often narrowly limited. The spermatozoa pass from the testis into a vas deferens, which Ues to the outside of the corresponding ureter. The. Fig. 2i6.—Urinogenital organs of Pigeon. A'., kidney; U., iireter ; cl., cloaca; T., Testis; '., vx«^ de- ferens; 7'.j., seminal vesicle; ot'., ovar^'; oviduct- r 7-od rudimentary right oviduct ;y:^., funnel at end of oviduct. ' ' ' ' vasa deferentia, slighdy convoluted when full of sperms, open separately into the median compartment of the cloaca! In the adult pigeon, and in most birds, there is only one ovary ; that of the right side atrophies very early in life. The right oviduct is represented by a small rudiment close to the cloaca. The ovary is covered with follicles containing ova at various stages of ripeness. As these ova beconie dilated with yolk and otherwise mature they burst from the ovary. 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 Thomson, J. Arthur (John Arthur), 1861-1933; Newbigin, Marion I. (Marion Isabel), 1869-1934; Smith, Preserved, 1880-1941. fmo. New York, D. Appleton & Co.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
