CONTENTS 
PAGE 
Prof. H. Marshall Ward, On the Question of “ Predisposition ” and 
“ Immunity” in Plants 307 
Mr J. Graham Kerr, On the Genito-urinary Organs of Dipnoan Fishes . 329 
Dr George H. F. Nutt all, Further Observations upon the Biological 
Test for Blood 334 
Messrs H. 0. Jones and 0. W. Richardson, Note on a Method for 
determining the Concentration of Hydrogen Ions in Solution . . 337 
Mr R. S. Morrell, On the oxidation of Glucosone to Trioxybutyric Acid 340 
Mr J. C. Crocker, On the formation of Di-nitro-phenoxazines . . 342 
Mr J. C. Crocker, On the interaction of Thiocyanates , Picric Chloride , 
and Alcohols 347 
Dr A. C. Dixon, Note on the Reduction of a Ternary Quantic to a Sym- 
metrical Determinant 350 
Mr J. H. Grace, On the Zeros of a Polynomial 352 
Mr Henry J. Horstman Fenton, On Oxidation in Presence of Iron . 358 
Mr H. C. Pocklington, On a method of increasing the sensitiveness of 
Michelson's Interferometer . . .375 
Mr P. Y. Bevan, On the Influence on Light reflected from and transmitted 
through a Metal of a Current in the Metal 380 
Mr Harold A. Wilson, On the Hall Effect in Gases at Low Pressures . 391 
Mr G. F. C. Searle, On the Coefficient of Mutual Induction for a circle 
and a circuit with two parallel sides of infinite length . . . 398 
Mr K. Ramunni Menon, Notes on Semper' s Larvae (with Plate IY) 
. 407 
