Index. 389 



Orr, W. M c F., On the product J m (x) J n (x), 93. 



On Semi-convergent Series (Trans, xix.), 189. 



Pain, B. H., and Duckworth, Eskimo from Labrador, 286. 

 Palaeospondylus, Traquair (Kerr), 298. 

 Periodic Movement of Plants (Pertz and Darwin), 259. 

 Pertz, D. F. M., and Bateson, Inheritance of Variation in corolla of 

 Veronica Buxbaumii, 78. 



and Darwin, Periodic Movement of Plants, 259. 



Pocklington, H. O, On the Symbolic Integration of certain Differential 

 Equations in Quaternions, 59. 



On sensitiveness of Radiant Heat detectors, 66. 



Poincar^, H., Sur les Groupes Continus (Trans, xviii.), 187. 

 Polypterus and Protopterus (Budgett), 236. 



Potential Fall at the Electrodes in Conduction produced by Rontgen rays 



(Zeleny), 14. 

 Proceedings of the Session 1898—1899, 183. 

 1899—1900, 377. 



Quadratic Complex Numbers (Western), 10. 

 Quadrics, apolar systems of (Grace), 10. 



Quadric, five straight lines in four dimension space should lie on a (Rich- 

 mond), 210. 

 Quaternions, Symbolic Integration of certain Equations in (Pocklington), 59. 



Radiant Heat Detectors, Sensitiveness of (Pocklington), 66. 

 Richmond, H. W., On the condition that five straight lines situated in space 

 of four dimensions should lie on a quadric, 210. 



On Minimal Surfaces (Trans, xviii.). 



On the simplest algebraical minimal curves and the derived real minimal 



surfaces (Trans, xix.), 301. 



On rational space curves of the fourth order (Trans, xix.), 331. 



Rontgen rays, secondary (Townsend), 217. 



ionization produced by (Thomson), 10. 



convection currents in conduction produced by (Zeleny), 14. 



Rothschild, Hon. N. O, Elected Fellow, 380. 



Schuster, A., On the Periodogram of Magnetic Declination as obtained from 

 the records of Greenwich Observatory 1871 — 1895 (Trans, xviii.), 188. 

 Searle, G. F. C, Apparatus for measuring the extension of a wire, 318. 

 Secondary Sexual Characters in Animals (Barrett-Hamilton), 279. 

 Seward, A. C, and Hill, Lepidodendron Wunschianum, 38. 



On the Binney Collection of Coal-Measure Plants, 137. 



Wealden Plants from Bernissart, 259. 



Sharp, D., Modification and Attitude of Idolum diabolicum, 175. 

 Sharpe, H. J., Reflection of Sound at a Paraboloid, 101. 



