Studies in Dedifferentiation. 
II. Dedifferentiation and resorption in 
Perophora. 
By 
Julian §S. Huxley, 
New College, Oxford. 
With Plates 26-28 and 1 Text-figure. 
CONTENTS. 
PAGE 
1. INTRODUCTION ; ; : : : ; Z : . 643 
2. DEDIFFERENTIATION F ‘ ; 2 ‘ : : . 645 
(a) General : : ; : : : : : . 645 
(b) Simple Dedifferentiation (Clavellina type) : 2 . 647 
(c) Dedifferentiation with Resorption . é : : . 648 
3. EXPERIMENTS WITH POTASSIUM CYANIDE : d : #655 
4, EXPERIMENTS ON ANIMALS WITHOUT CIRCULATION. F . 656 
5. EXPERIMENTS witH Low TEMPERATURE . ‘ 3 : . 660 
6. MiIscELLANEOUS NOTES ON PEROPHORA . : : ; . 660 
7. EXPERIMENTS ON OTHER SPECIES . : : ; : . 662 
8. DISCUSSION . : F ; : ‘ : 3 ; OG 
9, SUMMARY . : ‘ : ; ; : 3 ‘ - 692 
1. INTRODUCTION. 
THE observations of Driesch (1906) and E. Schultz (1907) and 
myself (unpublished) upon the reduction or dedifferentiation of 
the social Ascidian Clavellina have been mainly morphological. 
Accordingly I decided, while in the United States, to take up 
the problem from the physiological aspect. The work was 
carried out at Weod’s Hole. Clavellina itself is not found 
there, but another social Ascidian, Perophora viridis, 
is common, and proved to be a useful form for experimental 
