EDITORIAL. 
4. This thesis is also supported by the fact, proved experi¬ 
mentally, that animals, once infected with tuberculosis, after a 
certain time cannot be infected de novo, even if the original 
tuberculosis progresses or even would bring on death of the ani¬ 
mal. 
5. This fact may be observed in man. For instance, the 
cervical and submaxillary glands are not infected in phthisic indi¬ 
viduals, although their buccal cavity is constantly occupied by 
virulent tuberculous bacilli. 
6. Another argument in favor of the hematogenous origin 
of pulmonary tuberculosis is the relative immunity following 
mitral stenosis, which causes congestion or even increase of pres¬ 
sure in the pulmonary blood vessels, while on the contrary, in¬ 
sufficiency of the pulmonary valve ends regularly with tuber¬ 
culosis. 
7. The extremely frequent lesions of the bronchial lymphatic 
glands are easily explained by the direct connection of the entire 
lymphatic system, but specially, as it is easy to demonstrate by 
experiments on animals, by the direct connections of the 
(bronchial lymphatic glands and the supraclavicular and cervical 
glands on one side and the retroperitoneal and mesenteries of 
the abdomen on the other. 
* 
* * 
Prof. A. Calmette of Lille presented the following conclu¬ 
sions on the same subject: 
1. It is established that conceptional infection is only a small 
factor in the propagation of tuberculosis. 
2. In the immense majority of cases, in man, the bacillar 
contamination takes place in youth and infancy. It is proved by 
the extreme frequency of the positive reactions to tuberculine in 
children between one and fifteen years old. In large cities, one- 
year-old children, which were free from disease at birth, are al¬ 
ready infected in the proportion of 10%. This goes up to 50% 
in children between 1 and 5 years and to 80% between 5 and 15. 
In adults it reaches or goes sometimes further to 87%. 
