20 



TUBERCULOSIS, HEREDITY 



for me only one possible explanation : the hereditary 

 constitutional factor is immensely more important than 

 the infection-factor, and when we devote all our 

 national energies to isolation and segregation, we are 

 wasting a very large proportion of our efforts. I have 

 selected two tables — one from my own work and one 

 from Dr. Goring's, deduced by quite different methods, 

 with wholly different hypotheses and using absolutely 

 unlike material. Both are reduced to i,ooo cases. 



TABLE X. ILLUSTRATIVE TABLES. 

 Pearson : Parent and Child. 

 Parent 



Child I y 



Totals 



Cliild 



NotT. 

 T. 



Totals 



Correlation 

 0-55 



Transfer 



+ 17 



17 



17 



+ 17 



Correlation 

 052 



Transfer 



+ 17 



-17 



-17 



+ 17 



In both cases the tables correspond to a transfer from 

 the independent probability of 34 individuals, as against 

 the 6 in the case of husband and wife. The correla- 

 tions are respectively 0.52 and 0-55. I think these results 

 should convince you, as they have already convinced 

 me, that tuberculosis has not to be considered solely 

 from the standpoint of infection— that the constitutional 

 or hereditary factor is of far greater significance. 



