Interspecific relationships of oviducal materials as related to fertilization in amphibia.

Experiments are described in which eggs of Rana species were treated prior to insemination with antisera prepared against oviducal materials of Rana, Bufo, and Ambystoma species. Three types of treatment with antisera were employed. Eggs of Rana pipiens and R. clamitans were treated with antisera against materials prepared from whole oviducts, or from upper and lower segments of oviducts, of R. pipiens, R. clamitans, R. sylvatica, R. catesbeiana, Bufo americanus, B. marinus and Ambystoma mcxicanum. Eggs of R. pipiens were treated with antisera against materials from whole oviducts, or from upper, middle or lower oviducal regions, of R. pipiens, which had been absorbed with materials from whole oviducts of the species named above. Eggs of./?, pipiens were treated with antisera against materials from whole oviducts, or from upper, middle or lower oviducal segments of R.pipiens, which antisera had each been absorbed with material from whole, upper, middle or lower oviducts of Rana species. The results indicated that treatment with antisera against oviducal materials of Rana origin was inhibitory to fertilization of Rana eggs, while treatment with antisera against oviducal materials from other amphibian genera was not. The experiments with absorbed antisera indicated that the secretion by the oviducts of R. pipiens of components also occurring in other Rana species is regionally localized in the oviduct. The relationships of secretions of amphibian oviducts to fertilization is discussed in connexion with the histochemically demonstrable complexity of the jelly envelopes around eggs.