vi 
Contents. 
PAGE 
Notes on the Genus Ficus (Tourn.), Linn. By Joseph 
Burtt-Davy. (With Plates xii., xiii., and two text figures) 365 
A New Species of Mesemhrianthemum from the Transvaal. 
By Joseph Burtt-Davy. (With two text figures) . . 369 
The Eesultant of a Set of Homogeneous Lineo-linear 
Equations. By Thomas Muir 373 
On Some Meteorological Conditions Controlling Noc- 
turnal Eadiation. By J. E. Sutton .... 381 
On the Variation in the Value of the Atmospheric 
Electrical Potential with the Altitude. By W. A. 
Douglas Eudge 395 
Eespiration and Cell Energy. By Horace k. Wagner . 405 
Presidential Address. By S. S. Hough .... 419 
