No. 6. DEPARTMENT OP AGRICULTURE. 131 



bacillus is at least as virulent as the human for man when intro- 

 duced in such manner. We know from experimental as well as 

 clinical evide^ice that the skin is the tissue most unfavorable to the 

 jrrowth of the tubercle bacillus. If, then, the bovine bacillus can 

 successfully invade the skin and multiply there, with the production 

 of characteristic changes, it seems we are fully justified in believing 

 that organs and tissues that are known to ofler favorable soil to the 

 human bacillus will also prove favorable to the bovine organisms. 

 On (he other hand, I kiiow of no animal which is susceptible to the 

 human bacillus yet immune to the bovine. Birds are equally refract- 

 ory to both, a small proportion of those inoculated or fed with 

 either succumbing to tuberculosis. 



Tuberculous Infection Ihrough Food. — Koch bases his opinion 

 as to the non-transmissibility of bovine tuberculosis to man largely 

 on the alleged rarity of primary intestinal tuberculosis. He says: 

 ''If the bacilli of bovine tuberculosis were able to infect human be- 

 ings many cases of tuberculosis caused by the consumption of 

 aliments containing tubercle bacilli could not but occur among the 

 inhabitants of great cities, especially children." "That a case of 

 tuberculosis has been caused by aliments can be assumed with cer- 

 tainty only when the intestine suffers first — i. e., when a so-called 

 primary tuberculosis of the intestine is found." He says that he 

 has seen only two such cases; that at the Charity Hospital, in Ber- 

 lin only ten cases were seen in five years; that among 933 cases of 

 tuberculosis in children at the Emperor and Empress Frederick's 

 Hospital for Children, Baginsky never found tuberculosis of the in- 

 testine without simultaneous disease of the lungs and bronchial 

 glands; that Biedert found only sixteen cases of primary intestinal 

 tuberculosis among 3.104 children examined post mortem. 



The assumption that the proportion of tuberculosis caused by 

 good is correctly revealed by the lesions of the intestine or mes- 

 enteric glands is certainly erroneous, and leaves out of consideration 

 entirely at least one very important avenue of infection. 



Infection Through the Tonsils. — The numerous observations made 

 of late years leave no doubt that the tonsils sometimes act as the 

 port of entry for the tnbrcle bacillus. As well put by Baup. "dis- 

 cussion is only possible as to the greater or less frequency of these 

 lesions, and their pathological importance." a position sustained 

 not only by the work of other observants but by his own. in which 

 he examined the tonsils from those cases only in which tuberculosis 

 of the lungs was absent and other ports of entry could be excluded. 

 Dieulafoy, by the inoculation of guinea-pige. found tuberculosis in 

 fifteen of ninety-six cases. Latham, who was careful to employ 

 only the interior portions of the tonsils, in forty-five consecutive cases 



