PKOCEEDINGS 



OP THE 



CAMBRIDGE PHILOSOPHICAL 

 SOCIETY 



VOL. XX. PART III. 



[Lent Term 1921.] 



CAMBRIDGE 



AT THE UNIVERSITY PRESS 



AND SOLD BI 

 DEIGHTON, BELL & CO., LIMITED, 

 AND BOWES & BOWES, CAMBRIDGE. 



CAMBRIDGE UNIVERSITY PRESS. 



C. F. CLAY, MANAGER 



FETTER LANE, LONDON, E.G. 4 



I92I 



Price Eight Shillings and Sixpence Net 



May 1921. 



