Oviducal and Uterine Fluids

Our knowledge about the oviducal functions is still incomplete. The Fallopian tube is not merely a conduit for the passage of spermatozoa and ova, but it provides a favourable environment, by virtue of its luminal fluid, for the gametes and for the fertilized and cleaving ovum (Hamner & Fox, 1968, 1969; Stegner, 1969; Hamner, 1971). Furthermore, the uterine environment doubtless provides shelter and nourishment for the developing and implanting conceptus. During the whole period of gestation the embryo depends upon the milieu provided by the maternal organism, and even during pre-implantation there exists a well documented dependency of the blastocyst upon the maternal substrates, provided by the oviducal and uterine tissues. From the very beginning of development, from the establishment of an individual genome, there exist two closely related systems: the embryonic and the maternal system. But, taking into consideration morphological and biochemical analyses, one must recognize that both these