A COMPARISON OF THE LIFE CYCLE 

 OF CEITHIDIA WITH THAT OF 

 TRYPANOSOMA IN THE IN- 

 VERTEBRATE HOST 



A THESIS ACCEPTED IN PAETIAL SATISFACTION OF 

 THE REQUIREMENTS FOR THE DEGREE OF 



DOCTOR OF PHILOSOPHY 

 AT THE UNIVERSITY OF CALIFORNIA 



BY 



IRENE AGNES McCULLOCH 



1919- 



