Vol. VI. Part IV. 
March 1909 
BIOMETEIKA 
A JOURNAL FOR THE STATISTICAL STUDY OF 
BIOLOGICAL PROBLEMS 
FOUNDED BY 
W. F. R. WELDON, FRANCIS GALTON and KARL PEARSON 
EDITED 
IN CONSULTATION WITH FRANCIS GALTON 
AND IN COLLABORATION WITH 
C. B. DAVENPORT W. R. MACDONELL 
W. PALIN ELDERTON RAYMOND PEARL 
BY 
KARL PEARSON 
CAMBRIDGE 
AT THE UNIVERSITY PRESS 
LONDON: FETTER LANE, E.G. 
(C. F. CLAY, Managbk) 
AND H. K. LEWIS, GOWEE STREET 
EDINBURGH : 100, PBINCES 8TBEEI 
NEW yobk: e. p. putnam's sons 
BERLIN : A. ASHEB AND CO. 
LEIPSIC : BBOCKHAUS 
BOIitBAT AND CALOniTA : MAOMILLAN AND CO., LIMITED 
Entered at the New York Post Office as Second Class Matter 
Price Ten Shillings net. 
mum 
{Ittued April 7, 1909] 
