THE INCLUSION OF VISCERA AND CARCASSES OF TUBERCULOUS ADULT SALMON IN THE DIET OF JUVENILE SALMONIDS is considered to be the major source of mycobacterial infections in hatchery-reared fish (Wood and Ordal, 1958; Ross, Earp, and Wood, 1959). In considering additional modes of infection, we speculated about transovarian transmission or a mechanical process arising from contamination of the ova at the egg-taking stage with subsequent entry of the bacteria into the egg at the time of fertilization. This paper is a report on observations made during an experiment designed to test the latter theories.