The Development of Leucocytozoon canis in the Tick with a Reference to the Development of Piroplasma

In the last issue of Parasitology a description is given by Wenyon (5) of the developmental cycle of Leucocytozoon canis in the tick Rhipicephalus sanguineus . Wenyon refers to the description of the development given by me (2), but rightly points out that one stage, that of the large compound cysts, was overlooked. The surmise, however, that these large and easily ruptured cysts were overlooked owing to their having been broken up in the preparation of films is only part of the truth. A full explanation involves facts in regard to the development of this parasite which have not been touched upon by Wenyon; it is possible, as will be seen shortly, that Wenyon's description of the cycle, like mine, involved a considerable error. In this respect, as a result of work not yet published, I am able to supplement what has been written on the subject.