CONTENTS III 



Curvatures (Further researches on the antiphototropic) occurriné in the 

 coleoptiles of Avena. 158. 



Cyclic derivatives of mannitol. 335. 



DiK (H. W. J.) and P. Zeeman. A connection between the spectra of 

 ionized potassium and argon. I. 67. 



DiNGEMANSE (Elisabeth) and J. p. WiBAUT. The action of sodium- 

 amide on pyridine, and some properties of z-aminopyridine. 458. 



Dislocation theory (The) of catalysis. 210. 



Dissociation constants (The) of sulphonacetic and z-sulphonpropionic 

 acids. 359. 



Dooren de Jong (L. E. den) v. Jong (L. E. den Dooren de). 



Dubois (Eug.). Phylogenetic and ontogenetic increase of the volume of 

 the brain in vertebrata. 230. 



DuiN (C. F. van) and H. R. Kruijt. Heterogeneous catalysis and the 

 orientation of adsorbed molecules. 324. 



Ehrenfest (P.) and G. Breit. A remarkable case of quantization. 2. 



Electric resistance (On the) of pure metals etc. X. Measurements con- 

 cerning the electric resistance of thallium in the temperature field of 

 liquid helium. 443. XI. Measurements concerning the electric resistance 

 of ordinary lead and of uranium lead below 14° K. 451. 



Electrons (On the mean free path of slow) in neon and argon. 90. 



Elliptic pencils (Explanation of some interference-curves of uni-axial and 

 bi-axial crystals by superposition of). III. 81. 



Emigration (On the causes of the) of leukocytes. 36. 



End-corpuscles (On the regeneration of sensitive) after section of the 

 nerve. 319. 



Equilibria (In-, mono- and divariant). XXII. 341. 



Excitation potentials (On the) and ionization potentials of neon and 

 argon. 179. Appendix. 442. 



Feringa (K. J.). On the causes of the emigration of leukocytes. 36. 



Flora (Ueber einen fossilen Baumstamm von Bolang (Java), ein Beitrag zur 

 Kenntnis der fossilen) Niederlandisch-Indiens. 9. ' 



FoRMENKOEFFiziENTEN (Ueber Determinanten aus). 354. 



Frog-muscle (On the progress of the veratrin-poisoning of the striated). 364. 



FuNKE (G. L.). The influence of hydrogen ion concentration upon the 

 action of the amylase of Aspergillus niger. 6. 



Galvanogram of man (On respiratory oscillations in the). 225. 



Gas mixtures (On the separation of) by diffusion in a flowirig gas. 434. 



Gas pressure (On centres of luminescence and variations of the) in spectrum 

 tubes at electrical discharges. II. 463. 



