UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 19, No. 6, pp. 201-274, plates 7-14, 4 figures in text. December 3, 1919 



BINARY FISSION IN COLLODICTYON 

 TRICILIATUM CARTER 



ROBERT CLINTON RHODES 



V/AR 



CONTENTS 



PAGE 



Introductory and historical 201 



Material and technique 204 



General morphology 209 



Habits and activities 219 



Mitosis 221 



Resting stage 221 



Unequal constriction of the karyosome 223 



Mitosis 224 



Prophase 22(5 



Metaphase 229 



Anaphase and telophase 231 



Summary of observations 232 



Discussion 234 



Classification and relationships 234 



Parasitism and symbiosis 239 



Mitosis 241 



Kinetic membrane 250 



Inheritance in binary fission 252 



General Summary 254 



Literature cited 255 



Explanation of plates 260 



INTRODUCTORY AND HISTORICAL 



In February, 1916, I found in an aquarium containing goldfish 

 a dominant and persistent, free living flagellate which seemed to 

 warrant further investigation. Being large and transparent, except 

 when filled with green and opaque inclusions, and occurring in quan- 

 tities, it presented an opportunity for continuous and repeated 



211921 



