PKOFESSOR PEAESON'S CONTRIBUTIONS TO OSTEOLOGY. 457 



Civilised and Uncivilised Eaces." By Miss Alice Lee and Karl 

 Pearson." Proc. i^./S, vol. Ixi. p. 343. -' 



Do. do. " On the Inheritance of the Cephalic Index." By 

 Miss Cicely D. Fawcett and Karl Pearson. Froc. B. S., vol. Ixii. 

 p. 413. 



Do. do. "V. On the Reconstruction of the Stature of 

 Prehistoric Eaces." By Karl Pearson. Fhil. Trans., vol. 192 A. 



" Data for the Problem of Evolution in Man. — I. A First 

 Study of the Variability and Correlation of the Hand," By 

 Miss M. A. Whitely and Karl Pearson. Froc. li. S., vol. Ixv. 

 p. 126. 



It is to be borne in mind that the questions of the correlation, 

 variation, etc., of the different specific organs, dealt with in the 

 above memoirs, are to be regarded as illustrative applications of 

 certain mathematical methods, the development of which is the 

 chief object of the papers. And although it is in their applica- 

 tions that these methods are of interest to the biologist, yet the 

 paucity of data of the right kind at present available robs the 

 results of much of their value. These illustrations, therefore, 

 serve rather to indicate the way in which it is proposed to deal 

 with the more numerous and accurate observations which are 

 now being collected. 



We shall first consider in outline the general theory of the 

 mathematical treatment of variation, correlation, etc., and then 

 briefly summarise some of the practical applications to osteo- 

 logical statistics. 



Theoretical. 



Frequency Folygons. — Let a large number (say 1000) of any 

 organ ^ belonging to a homogeneous population be taken at 

 random and measured. And let the measurements be sorted into 

 groups in such a way that those in any particular group differ only 

 within a small specified range. For example, if the measure- 

 ments be of stature, they might be sorted into groups differing 

 by half an inch ; so that the measurements lying between 60 



^ The word 'organ' is used throughout in tlie Pearsouian sense of ''any 

 measurable characteristic of an organism." 



