Studies were uncertaken to obtain core information about the role of the oviduct in normal cows and its contribution to infertility in repeat breeder cows. The investigations involve examination of slaughterhouse material and the evaluation of clinical tests for oviduct patency. Intial studies, using fluid and a particle suspension to demonstrate the details of patency of the oviducts of cow and heifer genital tracts, suggested then a corporation of oviducts which produve patent to the fluid were blocker to the paspare of particles. In the live animal, a pacific for of the phonolsuplpherthloe bye test was evolved which proved accurete in diagnosing uilaterial and lilateral occulaion the eviducts. However this test could not be need to diagnesse partial occlusion or narrowing of the oviduces. The use of supervolusion using pregrant rare serum gonadotrophin, and non-surgical embryo recovery was studied as a reans of assessing oviduct. The eggs collected were examined for normality using the light microscope and preliminary studies in preparation and results of the use of the scaning electron microscope are described.