CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF THE .MUSEUM OF COM- 

 PARATIVE ZOOLOGY AT HARVARD COLLEGE UNDER THE DIRECTION OF 

 E. L. MARK, No. 219. 



CONTRIBUTIONS TO THE PHYSIOLOGY OF 

 REGENERATION 



IV. REGULATION OF THE WATER CONTENT IN REGENERATION 



SERGIUS MORGULIS 



SEVEN FIGURES 



CONTENTS 



The curve of regeneration and the curve of growth. A parallelism 321 



The role of water in growth 325 



Method of investigation 328 



Experiments on Podarke obscura : 331 



First series, Experiment A 331 



Experiment B 337 



Experiment C 339 



Second series, Experiment D 340 



Experiments on Diemyctylus viridescens 344 



Summary 347 



Bibliography 348 



THE CURVE OF REGENERATION AND THE CURVE OF GROWTH 



Recent studies on regeneration have revealed the fact that the 

 process is divisible into a series of stages, marked by different de- 

 grees of intensity of the regenerative energy. This periodic change 

 in the regenerative energy in the course of the regeneration of an 

 organ was discovered independently by Miss Durbin ('09) and 

 myself ('09) while experimenting with different organisms and 

 with different objects in view. The close similarity of the results 

 of both studies is especially noteworthy, since the quantitative 

 determinations were based upon the amount of differentiation of 

 the regenerating organ in the former case, and upon the amount 

 of its elongation in the latter. But regardless of the difference of 



321 



