THE 



SOUTH AFRICAN JOURNAL 

 OF SCIENCE: 



BEING THE ORGAN OF THE 



SOUTH AFRICAN ASSOCIATION 



FOR THE 





ADVANCEMENT OF SCIENCE, 



Issued Monthly. 



VOL. IX. APRIL, 1913. NO. 9. 



CAPE TOWN. 



PUBLISHED BY THE ASSOCIATION. 



ig j 3 [Price 2s. 



