In a survey of 1000 cattle, Cysticercus bovis was found in 31.7% and Echinococcus granulosus in 25.5%. In spite of their close generic relationship, they do not appear to cause mutual interference, i.e. the presence of one does not preclude that of the other, although the figures are suggestive of some relationship between them. Males were found to contain C. bovis cysts more frequently than females but in the case of hydatid cysts there was no difference between the sexes. The incidence of C. bovis decreased and that of E. granulosus increased slightly with age but neither figure was statistically significant for the animals in this survey.