UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 20, No. 16, pp. 373-390, plate 37, 1 figure in text August 16, 1923 



ON THE MORPHOLOGY AND BEHAVIOR OF 



PENTATRICHOMONAS ARDIN DELTEILI 



(DERRIEU AND RAYNAUD) 



BY 



CHARLES ATWOOD KOFOID .\nd OLIVE SWEZY 



CONTENTS 



Introduction 373 



Acknowledgments 375 



Material ^ 376 



Morphology 378 



Eeproduetion 382 



Behavior 382 



Survival in water 385 



Culture 386 



Summary 387 



Literature cited 388 



Explanation of plates 390 



INTRODUCTION 



The evolution of the polymastigote fiagellates has progressed by 

 t-vro methods: (1) increase in the number of the anterior or other 

 flagella, and (2) differentiation in structure and specialization in 

 function among the flagella. The first method has given rise ultimately 

 to the Hypermastigina which, in their most highly specialized genera, 

 are covered over their entire surface by flagella, hundreds or thou- 

 sands in number. The second method has resulted in the development 

 within the Polymastigina of organs such as the trailing, ribbon-like 

 flagellum of Devescovina, the undulating membrane and the axostyle 

 of Trichomonas, and the flagellar lines of Pyrsomjmpha. The 

 morphological constancy in number of these fundamental organelles 



