According to Wakeley (1943-44), the majority of epididymal cysts in man arise in the vasa efferentia, the bridge of tissue between the testis and epididymis. The ability of two sterilant chemicals to produce specific lesions of this nature in the rat (α-chlorhydrin—Ericsson, 1970; ethylenedimethanesulphonate—Cooper & Jackson, 1970) points to the need for further information on the vasa efferentia in relation to their susceptibility to damage in this manner. As there appears to be inadequate information on the course of these tubules, the present study was undertaken.
At post mortem, the testes resting in the scrotum of the rat present anterior and posterior surfaces and medial and lateral rounded borders. Serial longitudinal sections were made in both rat and mouse of the entire testis-epididymisvas complex, from the anterior to the posterior