•Jalfc'l^ 



THE 



SOUTH AFRICAN JOURNAL 



OF SCIENCE: 



BEING THE ORGAN OF THE 





SOUTH AFRICAN ASSOCIATION 



FOR THE 



ADVANCEMENT OF SCIENCE, 



Issued Monthly, 



/OL. IX. 



AUGUST, 1913. 



NO. 13; 



CAPE TOWN. 



PUBLISHED BY THE ASSOCIATION. 



1 91 3 



[Price 2s. 



