STUDIES IN THE LIFE HISTORY OF EUGLENA* 

 I. EUGLENA AGILIS, CARTER. 



WOOLFORD B. BAKER, 



COLUMBIA UNIVERSITY, ZOOLOGICAL LABORATORY, AND EMORY 

 UNIVERSITY, DEPARTMENT OF BIOLOGY. 



CONTENTS. 



I. INTRODUCTION 321 



II. ACKNOWLEDGMENTS 322 



III. MATERIAL AND METHODS 322 



IV. GENERAL MORPHOLOGY 324 



1 . Diagnostic Characters 324 



2. Gullet and Reservoir 325 



3. Nucleus 326 



4. Chromatophores 327 



5. Motor Apparatus 327 



V. REPRODUCTION 328 



1. Nuclear Division 329 



(a) Changes in the Endosome 329 



(&) Formation of Chromosomes 330 



(c) Migration of the Nucleus 331 



(d) Metaphase 331 



(e) Anaphase 332 



(/) Telophase 332 



2. Division of Gullet and Reservoir 333 



3. Division of the Body 334 



4. Behavior of Chromatophores During Mitosis 335 



5. The Flagellum and History of Kinetic Elements 336 



VI. DISCUSSION 337 



1 . The Resting Nucleus 338 



2. The Endosome 339 



3. Mitosis 347 



4. The Residual Mass from the Kinetic Complex 350 



VII. SUMMARY AND CONCLUSIONS 352 



VIII. LITERATURE CITED 354 



IX. DESCRIPTION OF PLATES 360 



INTRODUCTION. 



Attention has been called many times to the importance of 

 research on the Flagellates because of their relatively simple 

 structure, their apparent position at the bottom of the scale of 



* Submitted in partial fulfillment of the requirements for the degree of Doctor 

 of Philosophy, in the Faculty of Pure Science, Columbia University. 



321 



