lO 



TUBERCULOSIS, HEREDITY 



downward in the social scale the chances that a tuber- 

 culous husband will have a tuberculous wife diminish. 

 This is a remarkable state of affairs if it has to be 

 explained by infection ! Pope has collected statistics of 

 phthisis in husband and wife from 40 medical publica- 

 tions. If all the 41,786 couples dealt with by Pope be 

 clubbed together, as in our Table IV, we see the total 



TABLE IV. 



Pope : from Records of upwards of 40,000 Tuberculous Cases. 



Actual : Husband 



Correlation 

 0-17 



Corrected 

 Wi/e\^''^':^- 73^ '3^^ ^7' °-3i 



Totals 



Chance : 



M/-r 5 Not T. 

 Ivt/e j y 



Totals 



Transfer 



transfer of individuals has now risen from 6 to 20 ; but 

 this increase does not mean a higher correlation, for the 

 percentage of tuberculous in Pope's data is double that 

 of our Enghsh data, and the actual frequency is only 

 1-5 times, not ttvice, the chance frequency in the case of 

 both husband and wife being tuberculous. The corre- 

 lation is 0-17,^ but this is not directly comparable with 

 our previous results, for they v.'ere based on random 

 samples of the populations dealt with : here, every 



* The mean of the values of the 40 Tables treated separately given by- 

 Pope is o-i6, and agrees closely with the 0-17 obtained by combining them. 



