membrane only connecting them with the rest of the cord. 1862. Dr. D. H. Storer.
803. Foetal kitten, with the zonular placenta. 1847.
Dr. J. G. Warren.
804-6. Foetal sheep ; early months. 1854. Dr. J. Wyman.
807. The same, enclosed in the amnion. 1856.
Dr. J. Wyman.
808. Membranes of a sheep ; early months of gestation. Cotyledons injected by Dr. "W. 1854. Dr. J. Wyman.
809. Portion of the membrane of a calf, to show a cotyledon. 1858. Dr. J. Wyman.
810. Foetal cotyledon, from a cow ; a very fully and minutely injected specimen. 1867. Dr. J. C. Warren.
811. A foetal dog-fish, with the yolk-sac attached. "1849.
Dr. J. C. Warren.
812. A female Surinam Toad, showing the development of the ova in the skin of the back.
See Dr. J. Wyman's paper upon the subject in the Amer. Jour, of Science, for May, 1854. "The eggs," he says, " are transferred by the male to the back of the female, to which they adhere, and where they are impregnated ; their presence excites increased activity in the skin ; its thick- ness is gradually built up around each egg, which it at length nearly encloses in a small defined pouch." In the preparation, a section has been made through into the cavity that . exists beneath the skin of the back ; thus ex- posing many of the egg-sacs, most of which have been emptied, though in some of them the remains of the em- bryo, or of the yolk, are still seen.
813. A second specimen, with the abdomen laid open, and showing the ovaries filled with eggs. But, as they have not been discharged, the skin of the back, which has been cut through, has not undergone any change. These two
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