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A. 336. On the Formation of Definite Figures by the Deposition of Dust. By J. Bussell, Ph.D., 
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A. 337. The Spectrum of y Cygni. By Sir Norman Lockyer, K.C.B., F.R.S., and F. E. Baxandall, 
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A. 338. Quaternions and Projective Geometry. By Professor Charles Jasper Joly, Eoyal 
Astronomer of Ireland. Price 5s. 
A. 339. The Differential Invariants of a Surface, and their Geometric Significance. By A. E. Forsyth, 
M.A., Sc.D., F.E.S., Sadlerian Professor of Pure Mathematics in the University of Cambridge. 
Price 3s. GcZ. 
A. 340. On the Laws Governing Electric Discharges in Gases at Low Pressures. By AY. R. Carr, B.A., 
Post-graduate Student, University of Toronto. Price 2s. 
A. 341. On the Dependence of the Refractive Index of Gases on Temperature. By George AAL AValker, 
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A. 342. Solar Eclipse of 1900, May 28.—General Discussion of Spectroscopic Results. By J. Evershed, 
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A. 343. The Electrical Conductivity Imparted to a Vacuum by Hot Conductors. By 0. AA’’. Richardson, 
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A. 344. On the Formation of Definite Figures by the Deposition of Dust. By John Aitken, F.E.S. 
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A. 345. Title, Contents, Index, &c., Vol. 201. Price 6(7. 
A. 346. Bakerian Lecture.—On the Constitution of the Copper-Tin Series of Alloys. By C. T. Heycock, 
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Series B. — Biological. 
B. 212. The Development of Echinus Esculentus, together with some Points in the Development of 
E. Miliaris and E. Acutus. By E. AV. MacBride, M.A., D.Sc. (Lond.), sometime Fellow of 
St. John’s College, Cambridge; Strathcona Professor of Zoology in the McGill University, 
Montreal. Price 8s. 6(7. 
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B. 214. The Seed-Fungus of Lolium Temulentum, L., the Darnel. By E. Al. Freeman, M.S., University 
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B. 215. On the Histology of Uredo dispersa, Erikss., and the “Alycoplasm” Hypothesis. By 
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B. 216. The (Estrous Cycle and the Formation of the Corpus Luteiun in the Sheep. By Francis H. A. 
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B. 217. On the Evolution of the Proboscidea. By C. AAk Andrews, D.Sc., F.G.S., British Museimi 
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B. 218. Experiments in Hybridization, with Special Reference to the Effect of Conditions on Dominance. 
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