I 
BIOMETRIKA 
A JOURNAL FOR THE STATISTICAL STUDY OF 
BIOLOGICAL PROBLEMS 
FOUNDED BY 
W. F. R. WELDON, FRANCIS G ALTON and KARL PEARSON 
EDITED BY 
KARL PEARSON 
VOLUME XII 
November 1918 to December 1919 
i i i 
CAMBRIDGE 
AT THE UNIVERSITY PRESS 
LONDON: FETTER LANE, E.G. 4 
(C. F. CLAY, MANAfiEE) 
ANJ. H. K. LEWIS AND CO., Ltd., 136, GOWER STREET, \V.C. 1 
WILLIAM WESLEY AND SON, 28, ESSEX STREET, STRAND, W.C. 2 
CHICAGO : UNIVERSITY OF CHICAGO PRESS 
liOMBAY, CALCUTTA AND MADRAS : MACMILLAN AND CO., LIMITED 
TORONTO : J. M. DENT AND SONS, LIMITEI> 
TOKYO: THE MARUZEN-KABUSHIKI-KAISHA 
[All riglits reserved] 
