UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 16, No. I, pp. 1-22, pis. 1-4, 1 text figure September 16, 1915 



AN OUTLINE OF THE MORPHOLOGY AND 



LIFE HISTORY OF CRITHIDIA 



LEPTOCOIUDIS, SP. NOV. 



BY 



IRENE Mcculloch 



PAGE 



I. Introduction 1 



1. Occurrence 1 



2. Importance 2 



3. Methods 2 



4. Acknowledgments 3 



II. Morphology of flagellate in vegetative phase 3 



III. Movement 6 



IV. Longitudinal division 7 



V. Life-history 8 



1. Outline of the probable life-history 8 



2. Preflagellate (stomach phase) 8 



8. Flagellate (vegetative phase) 11 



4. Postflagellate (rectal phase) 11 



VI. Relation of parasite to host 13 



VII. Literature cited 14 



VIII. Explanation of plates 1.5 



I. INTRODUCTION 



1. Occurrence 

 The discovery of immense number.s of parasitic flagellates in the 

 intestinal tract of the box-elder bug, Leptocoris trivittatus, so com- 

 monly found about the buildings on the Campus of the University 

 of Kansas, led to a study of the structure and life-cycle of the para- 

 site. This new flagellate now under investigation is here called 

 Crithidia leptocoridis. The reasons for this will be deferred to a later 



