THE PERIODIC REORGANIZATION PROCESS IN 

 PARAMAECIUM CAUDATUM 



RHODA ERDMANN AND LORANDE LOSS WOODRUFF 



Oshorn Zoological Laboratory, Yale Universitij 



THIRTY-FIVE FIGURES (sEVEN PLATES) 



CONTENTS 



I. Introduction 59 



II. Material and methuiis 60 



III. The cytological phenomena of the reorganization process in Paramae- 



cium caudatum 62 



A. Descending phase 62 



B. Climax 69 



C. Ascending phase 72 



IV. Comparison of the cytological phenomena of the reorganization proc- 

 ess n Paramaecium caudatum and Paramaecium aurelia 76 



V. Discussions and conclusions 78 



VI. Literature cited 83 



VII. Explanation of plates 84 



I. INTRODUCTION 



In pre\'ious papers' there have been presented the morphologi- 

 cal and physiological details of a new reorganization process in 

 the life of Paramaecium aurelia, and the statement that the 

 phenomenon occurs also in Paramaecium caudatum. The 

 present paper is a study of this reorganization process, which we 

 term endomixis, in the latter species of Paramaecium. We 



1 Woodruff and Erdmann ('14, I): Complete periodic nuclear reorganization 

 without cell fusion in a pedigreed race of Paramaecium. Proc. Society for 

 Elxperimental Biology and Medicine, vol ii, Feb. 18. (Preliminary paper.) 



Erdmann and Woodruff ('14, II): Vollstiindige periodische Erneuerung des 

 Kernapparates ohne Zellverschmelzung bei reinlinigen Paramaecien. Biol. 

 Centr. Bd. 34. (Preliminary paper). 



Woodruff and Erdmann ('14, III): A normal periodic reorganization ^ocesa 

 without cell fusion in Paramaecium. Journal of Exper. Zoology, vol. 17, no. 4, 

 Nov. (Complete paper.) 



59 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 20, NO. 2 



