CONTENTS 



Prof. H. Marshall Ward, On the Question of "Predisposition" and 



"Immunity" in Plants . . 307 



Mr J. uaham Kerr, On the Genito-urinary Organs of Dipnoan Fishes . 329 



Dr George H. F. Nuttall, 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 Olucosone 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. V. Be van, 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 IV) . 407 



