. Outlines of zoology. Zoology. REPRODUCTIVE SYSTEM. 575 the foetal allantois, and has no functional connection with excretion. The urine is semi-solid, and consists largely of uric acid. Reproductive system.—In the male the testes are two white oval bodies suspended in a dorsal fold of mesentery. Along the inner surface of each runs the epididymis, which receives the vasa efferentia, and is continuous posteriorly with the vas deferens. The two vasa deferentia, after receiving the ureters, open by small papilla? into the cloaca. In connection with the cloaca there is a pair of eversible copula
. Outlines of zoology. Zoology. REPRODUCTIVE SYSTEM. 575 the foetal allantois, and has no functional connection with excretion. The urine is semi-solid, and consists largely of uric acid. Reproductive system.—In the male the testes are two white oval bodies suspended in a dorsal fold of mesentery. Along the inner surface of each runs the epididymis, which receives the vasa efferentia, and is continuous posteriorly with the vas deferens. The two vasa deferentia, after receiving the ureters, open by small papilla? into the cloaca. In connection with the cloaca there is a pair of eversible copulatory organs, postero-lateral in position. In the female the ovaries occupy a similar position to that of the testes in the male. The oviducts open far. Fig. 250.—Lung cu Chamaleo vulgaris, showing air-sacs. —After Wiedersheim. forward by wide ciliated funnels; as they pass backward they show a gradual increase in cross-section, but there is no line of demarcation between an oviducal and a uterine portion. Posteriorly, the oviducts open into the cloaca. The right reproductive organ tends to be larger and in front of the left. In many of the males the Wolffian body is well developed. Viviparous, or what is clumsily called ovo-viviparous, parturition is well illustrated by Zootoca vivipara, Anguis fragilis, Seps, etc., but most lay eggs with more or less calcaieous shells. In Trachydosaurus and Cyclodus the embryo seems to absorb food from the wall of the uterus. It is likely that Lacertilians existed in Permian ages, but their remains are not numerous before the Tertiary strata. Many instructive illustrations of evolutionary change are afforded by lizards. Thus there are numerous gradations in the reduction of the limbs, from a decrease in the toes to entire absence of limbs. The diverse forms of tongue and the varied positions of the teeth are also connected by gradations. From the variations of the wall - lizard (Lacerta muralis), Eimer elaborated most of his theory of ev
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Keywords: ., bookauthorth, bookcentury1800, bookdecade1890, booksubjectzoology
