CONTENTS. 

 No. 1, September 20, 1921. 



PAGE 



OsTERHOUT, W. J. V. Conductivity and permeability 1 



Maxwell, S. S. Stereotropic reactions of the shovel-nosed ray, 



Rhinohatus productus 11 



Maxwell, S.S. The stereotropism of the dogfish (Mustelus cali- 

 fornicus) and its reversal through change of intensity of the 

 stimulus 19 



Moore, A. R. Chemical stimulation of the nerve cord oi Lum- 



bricus terrestris 29 



Chambers, Robert. The formation of the aster in artificial par- 

 thenogenesis ?>?> 



Chambers, Robert. Studies on the organization of the starfish 

 egg 41 



Mitchell, Philip H., and Wilson, J. Walter. The selective 

 absorption of potassium by animal cells. I. Conditions 

 controlling absorption and retention of potassium 45 



Northrop, John H. Comparative hydrolysis of gelatin by 



pepsin, trypsin, acid, and alkali 57 



LoEB, Jacques. Donnan equilibrium and the physical properties 



of proteins. IV. Viscosity — continued 73 



LoEB, Jacques. The reciprocal relation between the osmotic 



pressure and the viscosity of gelatin solutions 97 



No. 2, November 20, 1921. 



Hecht, Selig. The nature of foveal dark adaptation 113 



Mitchell, Philip H., Wilson, J. Walter, and Stanton, Ralph 



E. The selective absorption of potassium by animal cells. 



II. The cause of potassium selection as indicated by the 



absorption of rubidium and cesium 141 



Carrey, Walter E. The relation of respiration to rhythm in the 



cardiac ganglion of Limulus polyphemus 149 



V 



