SEVENTH ANNUAL REPORT. 135 



seem to indicate that the lining cells of trachea and larynx pos- 

 sess considerable phagocytic power, 



PRIMARY INFECTION BY INHALATION. 



In a large percentage of the cases examined the lungs with 

 their lymph glands (especially the nodes situated at bifurcation 

 of tracheae) showed calcareous deposits, while other lymphatic 

 nodes were edematous or in process of caseation. I am led to 

 believe that primary infection takes place in the great majority 

 of cases by way of the respiratory tract. It seems to me probable 

 that tubercle bacilli enter the lungs and pass to communicating 

 glands without giving rise to preliminary lesions of the organ 

 with which they first come in contact. 



Of the smears taken from different parts of the larynx and 

 trachea where pulmonary tuberculosis existed in over 90 per cent, 

 of the cases tubercle bacilli were found in all parts of the tube. 



In a small number of cases tubercle bacilli could not be found 

 in trachea, though the lungs showed far advanced tuberculosis, 

 the tubercles showing calcareous degeneration. In one instance 

 (that of a small macaque monkey) one lung was totally func- 

 tionless, appearing as a large calcareous mass attached firmly to 

 the costal pleura ; the other being only moderately affected ; yet 

 the animal was apparently well nourished, as evidenced by the 

 amount of f^esh and fat present. In this case I was unable to 

 demonstrate the bacillus in the trachea. 



An interesting case was that of a spotted lemur which was 

 slightly injured, necessitating its isolation temporarily in the hos- 

 pital room. This animal presented a fairly healthy appearance 

 (excepting for the injury) with no clinical symptoms whatever 

 which led me to have the slightest suspicion that the animal was 

 tuberculous. Six smears were taken from throat and nostrils, 

 all of which showed tubercle bacilli in abundance, those of the 

 throat being particularly numerous. This animal was never 

 again put on exhibition, and I did not have to wait long to con- 

 firm my diagnosis, as the animal died within a few days. The 

 autopsy showed far-advanced pulmonary, pleural, and pericardial 

 tuberculosis. No lesions were present in other organs. 



INFECTION BY INGESTION. 



While one must take into consideration the possibility of pri- 

 mary invasion taking place by the intestinal canal through the 

 bacilli taken in with food or contaminated drinking water, this, 



