REPORT 



OP THE 



Eighteenth Annual Meeting 



OF THE 



SOUTH AFRICAN ASSOCIATION 



FOR THE ADVANCEMENT OF SCIENCE, 

 Being Volume XVll of the South African Journal of Science. 



BU LAW AYO 



1920. 



JULY 1 4—1 7. 



JOHANNESBURG : 



PUBLISHED BY THE ASSOCIATIOX 



19 2 1. 



