2O2 The Story of the Bacteria 



spoken of above. The lymph-nodes at the 

 root of the lung not shown in the picture were 

 much enlarged and jet black. 



While, as we have seen above, there is a 

 certain hereditary predisposition to tuber- 

 culosis which is resident in the body cells 

 themselves and of the exact nature of which 

 we are quite ignorant, there is little doubt 

 that one of the most important reasons why 

 tuberculosis is apt to run in families is that 

 children and relatives of consumptives are 

 more liable than others to come in direct 

 contact with the disease-producing germs, 

 which have been thrown off from the bodies 

 of their house-mates under conditions which 

 permit of their transmission. This may take 

 place through sneezing and coughing or by 

 the drying of excretions and their conversion 

 into dust. What has long been considered 

 as hereditary transmission of tuberculosis is 

 largely household infection. 



Theatres and churches, especially the former, 

 are apt, as is well known, to be altogether 

 inadequately ventilated. The headache and 

 malaise which are so prone to follow a visit 



