Abstract
Mexican typhus virus can be passed through ticks by the method of rectal injection. The virus will remain alive in the ticks for at least 12 days. These studies, together with one of our preceding publications and the work of Dyer, demonstrate that there are at least three insects-bedbugs, fleas and ticks-which must be considered as possibilities in conveying typhus fever from an animal reservoir to man. Our work will be continued by a study of rats and mice caught in typhus regions such as Mexico City and its immediate vicinity, with a search for the virus in these rodents as well as an analysis of the insects found upon them or in the localities in which they are concentrated.