Contents. 
The Division of Holosticha scutellum. By K. R. Lewin. (Communicated 
by Professor Nurratt) 
Exhibition of living Termites. By Professor A. D, Imms 
On the greatest value of a determinant whose constituents are limited. 
(Proof of Hadamard’s theorem.) By Professor A. C. Dixon 
Expressions for the remainders when 6, 67, sin k6, cos k6 are expanded in 
ascending powers of sin @. By Professor A. C. Drxon 
A dust electrical machine. By W. A. Doucias Rupa@er, (One fig. in 
Text) 
On a mechanical vacuum tube regulator. By R. Warppineton. (One 
fig. in Text) : : : : ; 
Some Plants new to the British Isles. By C. E. Moss 
On some new and rare Jurassic plants from Yorkshire :—Kretmophyllum, 
a new type of Ginkgoulian leaf. By H. HamsHaw THomas. 
(Plates VI and VII) 
The Unstable Nature of the Ion in a Gas. By R. D. KurEeman, 
(Two figs. in Text) . 
Note on the Absorption of Cathode Rays by Metallic Sheets. By 
R. Wuippineton. (One fig. in Text) : 5 ‘ : 
The Influence of Molecular Constitution and Temperature on Magnetic 
Susceptibility. Preliminary Note. By A. E. OxuEy : 
A Chinese Flea-trap. By Epwarp HINnpDLE. .(Communicated by Pro- 
fessor NuTTALL.) (One fig. in Text) 
Some methods of measuring the surface tension of soap films, By 
G. F. C. Searie. (Ten figs. in Text) . 
Proceedings at the Meetings held during the Session 1912—1913 . 
A possible connexion between abnormal sex-limited transmission and 
sterility. By L. DoncastER 
The Flight of the House-Fly. By Epwarp Hinde. (Communicated by 
Mr C. WARBURTON) . : 
On the Dependence of the Relative Ionisation in various Gases by B Rays 
on their Velocity, and its bearing on the Lonisation produced oy 
y Rays. By R. D. Kureman . 
Note on a Dynamical sg ystem illustrating Fluorescence. By N. P. 
McCLeLAND 
On the Presence of certain Lines of Magnesium in Stellar Spectra. By 
F. E. BAxANDALL. (Communicated by Professor NEWALL) 
The proportions of the sexes of Forficula auricularia in the Scilly Islands. 
By H. H. BrinpuEy. (One map in Text) 
Vil 
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