CONTENTS. 



PAGE 



Mr "W. M°F.-Obe, On Semi-convergent Series . 189 



Mr C. T. R. Wilson, An Experiment on the Condensation of Clouds . 189 



Mr J. J. Lister, The Skeleton of Astrosclera compared with that of 



the Pliaretronid Sponges » . . .189 



Dr S. F. Harmer, Note on the name Balanogiossus . . . . 190 



Miss E. Dale, ; On certain outgrowths {Intumescences) on the green 



parts of Hibiscus vitifolius Linn. Plates VIII, IX, X. . . 192 



Mr H. W. Richmond, On the condition that Jive straight lines situated 



in a space of four dimensions should lie on a quadric . , .210 



Professor Liveing, On the Influence of Temperature, and of Various 

 Solvents, on the Absorption Spectra of Didymium and Erbium 

 Salts . . . . .... . . . . .213 



Mr H. Jackson, Researches in the Sugar Group . . . . .215 



Mr A. Hutchinson, On a New Mineral . . . •■'-.}]■• • - 216 



Mr John S. Townsend, Secondary Rontgen Rays . . . . .217 



Mr J. Graham Kerr, Note on hypotheses as to the origin of the Paired 



Limbs of Vertebrates . . . . . . . ' . . 227 



Mr J. S. Bitdgett, Observations on Polypterus and Protopterus . . 236 



Mr J. A. M c Clelland, On the Conductivity of Gases from an Arc and 



from Incandescent Metals . . . . . . . . 241 



