SEVENTH ANNUAL REPORT. 103 



facts in relation to it. In the majority of cases the disease has 

 been contracted before the animals reach the Park. Several an- 

 imals have died from advanced tuberculosis almost immediately 

 after their arrival. I am fully convinced that the average case 

 of monkey tuberculosis is contracted under the unfavorable con- 

 ditions usual in the quarters of the dealers, or under the still 

 more unhygienic surroundings prevailing in transit. The pri- 

 mary infection takes place generally in the cervical and bronchial 

 lymph nodes, and extension of the disease usually follows as 

 metastases from these foci. This also is, no doubt, the most 

 frequent story in the pulmonary tuberculosis of children, which, 

 I think, simulates closely in nearly every particular the history 

 of the disease as we find it among the monkeys. Pulmonar}' 

 tuberculosis is by far the most frequent form of the disease as 

 in man, but other types of the disease are also observed, for in- 

 stance, two cases of typical primary intestinal tuberculosis have 

 been discovered, both of which probably received their infection 

 in our cages. Pure cases of lymphatic tuberculosis are even more 

 frequent. In these instances the lymph nodes and the spleen are 

 the most frequent sites of the disease, the liver becoming involved 

 later. Generally cases of lymphatic tuberculosis terminate with 

 pulmonary involvement, though sometimes otherwise, as by 

 tubercular meningitis. 



The general character of the lesions produced in simian tuber- 

 culosis correspond very closely to those of the human, and the 

 bacilli found also simulate morphologically those of the human 

 infection. Xo comparative biological tests have, however, yet 

 been made by us. Chronic tubercular lesions are much more in- 

 frequent in the monkey, and the pronounced fibroid changes of 

 pulmonary phthisis as seen in the man have never been observed 

 by me in the monkey. Neither does one frequently find healed 

 tubercular lesions in the tissues, particularly in the lungs of these 

 animals, as in man. In man, dying of other than tubercular 

 disease, healed tubercles are present in from 50 per cent, to 80 

 per cent, of cases. I infer from these facts that the disease is 

 of a much more virulent form in the monkey, and that the rule 

 is death in infected animals, while in man the average case re- 

 covers. This observation may be likened to the characteristics 

 of the disease when it affects a primitive people, particularly one 

 in which tubercular infections are infrequent in their natural 

 habitat ; we may thus compare the primate tuberculosis to that 

 of the Indians, of the Esquimaux, or even to that of the negro, 

 in his native land. From this line of reasoning it appears that 



