37 
THE DEVELOPMENT OF LEUCOGYTOZOON CANIS IN THE 
TICK WITH A REFERENCE TO THE DEVELOPMENT 
OF PIROPLASMA. 
By Major S. R. CHRISTOPHERS, I.M.S. 
(Central Research Institute, Kasauli, India.) 
(With 2 Diagrams.) 
In the last issue of Parasitology a description is given by Wenyon (s) 
of the developmental cycle of Leucocytozoon canis in the tick Rhipi- 
cephalus sanguineus. Wenyon refers to the description of the deve¬ 
lopment 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 develop¬ 
ment 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. 
But little stress has been laid by Wenyon on the possibility that the 
forms supposed to be developmental forms might be merely stages in 
the development of some natural parasite of the tick. In this respect 
I shall also give the result of observations made since my first descrip¬ 
tion of this cycle. 
Development of the parasite in relation to the growth of the tick. 
In a previous publication I described the following stages of 
development in the body of the tick: 
1. The liberation of motile vermicides and the passage of these 
into cells of the gut {diverticulum) wall. 
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