Comparative observations on the morphology of the mammalian periovarial sac

The interspecific variation in the positional and mesenteric relationship of the mammalian oviduct to the ovary observed among 41 species is summarized by distinguishing eight morphological types of relationship. The recognition of types is based on wide species differences in: the position of the oviduct with reference to the mesosalpinxal fold and ovary; the extent to which oviducal mesenteries enclose the ovary in a periovarial sac; the degree of closure and method of formation of the peritoneal opening to the periovarial sac; and the morphology of the oviduct.