. The physiology of reproduction. Reproduction. THE FEMALE GENERATIVE ORGANS 535 quarter to half-an-hour. The average for multiparous women is twelve hours, eleven of which are occupied by the first, and one by the second stage. The duration of labour in primiparous women depends also upon age, being usuaUy more prolonged in elderly subjects. Parturition in other Mammalia In animals the process of delivery varies somewhat in the different animals. In the horse the foetus, which has been lying on its back during intra-uterine life, preparatory to birth. Fig. 131.—The first stage in the revoluti
. The physiology of reproduction. Reproduction. THE FEMALE GENERATIVE ORGANS 535 quarter to half-an-hour. The average for multiparous women is twelve hours, eleven of which are occupied by the first, and one by the second stage. The duration of labour in primiparous women depends also upon age, being usuaUy more prolonged in elderly subjects. Parturition in other Mammalia In animals the process of delivery varies somewhat in the different animals. In the horse the foetus, which has been lying on its back during intra-uterine life, preparatory to birth. Fig. 131.—The first stage in the revolution of the equine foetus. The os is dilated by the membranes, which have not yet ruptured. (After Franck. From Smith's Veterinary Physiology, Baillifere, Tindall & Cox.) changes on to its side and afterwards assumes the upright position, with its muzzle and forelegs in the direction of the pelvis. Dilatation of the passage foUows, and the foal is de- hvered head first. In the cow and sheep the movements which occur are essentially similar. It is stated that the alteration in the position of the foetus is not brought about by its own movements but by the uterine contractions. The revolution of the foetus prior to birth in the mare and cow is apparently re- sponsible for the torsion of the neck of the uterus and vagina which often occurs in these animals. Parturition in the mare is accompanied by a complete separation of the chorion from the uterine wall. As a conse-. 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 Marshall, F. H. A. (Francis Hugh Adam), 1878-1949; Cramer, William, 1878-1945; Lochhead, James. London, New York, Longmans, Green
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectreproduction, bookyea
