viii CONTENTS 



Hecht, Selig. The dark adaptation of the human eye 499 



Bailey, I. W. The significance of the cambium in the study of 



certain physiological problems. Plate 1 519 



Raber, Oran L. a quantitative study of the effect of anions 



on the permeability of plant cells 535 



Raber, Oran L. The antagonistic action of anions 541 



Reed, H. S. The nature of the growth rate 545 



LoEB, Jacques. On the cause of the influence of ions on the 



rate of diffusion of water through collodion membranes. 11. 563 

 LoEB, Jacques. The reversal of the sign of the charge of mem- 

 branes by hydrogen ions 577 



No. 6, July 20, 1920. 



Northrop, John H. The influence of the substrate concen- 

 tration on the rate of hydrolysis of proteins by pepsin 595 



ScHMiTZ, Henry. Enzyme action in Echinodontium tinctorium 



Ellis and Everhart 613 



GusTAFSON, F. G. Comparative studies on respiration. XL 

 The effect of hydrogen ion concentration on the respiration 

 of Penicillium chrysogenum 617 



Crozier, W. J. The analysis of neuromuscular mechanisms in 



Chiton 627 



Hampton, Harold Clark, and Baas-Becking, Lourens G. M. 

 The kinetics of the action of catalase extract from marine 

 algae, with a note on oxidase 635 



LoEB, Jacques. Quantitative laws in regeneration, II 651 



LoEB, Jacques. The reversal of the sign of the charge of col- 

 lodion membranes by trivalent cations 659 



Loeb, Jacques. Ionic radius and ionic efficiency 673 



Index to Volume II 689 



