Minutes of Proceedings. 
xxxi 
comparatively rapid ; a few milligrammes of a salt containing about one- 
thousandth of its weight of radium causes a very definite colouration at 
the end of 20 days, the first zone being then clearly defined. The coloura- 
tion must be due to B and Y, as well as X-rays and emanation. 
A New Species of Mesembryanthemum from the Transvaal ; and 
Notes on the Genus Ficus," by J. Buett-Davy. 
