Observations on the transmission of Theileria mutans in South Africa.

Four isolates of Theileria mutans obtained from geographically distant parts of South Africa by subinoculation of infected blood were found to be readily transmitted by the bont tick Amblyomma hebraeum. All attempts to transmit these isolates with Rhipicephalus appendiculatus were unsuccessful. Possible explanations for differences between these results and those reported by earlier workers in this country are discussed.