304 THE TUBERCLE BACILLUS 



so readily set up general progressive tuberculosis in the calf as does inocula- 

 tion " (English Commission).] Feeding is the most certain method of 

 infecting the tracheal and bronchial glands (Vallee, Calmette and Guerin). 

 The bacilli may pass through the intestinal wall without producing any 

 apparent lesion either of the mucous membrane or of the mesenteric glands 

 provided that very small doses of bacilli and young animals be used, condi- 

 tions, that is, similar to those obtaining in the spontaneously contracted 

 disease (Vallee). 



Calmette, Guerin and Delearde fed calves with O'l gram of bovine bacilli and 

 found that they reacted to tuberculin 45 days later. The tracheal and bronchial 

 glands were swollen and hard but not caseous, the mesenteric glands were normal in 

 appearance, but, on inoculation, both sets infected guinea-pigs. 



(b) Cattle can also be infected with some strains of bacilli of human origin 

 (Chauveau, Ravenel, Arloing, M. Wolff, Schottelius, Spronck and others). 

 [These strains were no doubt strains of bovine tubercle bacilli infecting 

 human tissues (vide ante). The English Commission has demonstrated that 

 the human tubercle bacillus is incapable of causing progressive tuberculosis 

 in bovine animals.] 



Schottelius fed bovine animals on several occasions with tuberculous sputum. 

 In cows he found a tuberculous enteritis with caseous glands ; and, in calves, 

 caseation of the sub-maxillary and mesenteric glands. [This should be read 

 in conjunction with the comment above. The English Commission investi- 

 gated two cases of pulmonary tuberculosis in which the sole infecting agent 

 was the bovine tubercle bacillus.] In calves, bacilli from human lesions 

 whether inoculated beneath the skin or into the lungs or veins produced 

 general tuberculosis (De Jong, Sturmann). Inoculation (sub-cutaneous and 

 intra-peritoneal) of human tuberculous material into calves may lead to a 

 rapid and generalized infection (Fibiger and Jensen, Eber) [if the bacilli of 

 human origin are of the bovine type not otherwise (English Commission)]. 



In two cases in which Eber obtained a very severe infection in calves the bacilli 

 were derived from children in whom only intestinal lesions were present. It may 

 be admitted that the children were infected by swallowing bovine bacilli but it is no 

 less true that human tuberculosis can infect calves and bovine tuberculosis children. 

 [It seems to be a perfectly justifiable inference from the work of the English Com- 

 mission that the bacilli used by Eber in which he produced a severe infection in 

 calves must have been derived from children suffering from an infection with bovine 

 bacilli. Tubercle bacilli of the human type merely give rise to a slight and retro- 

 gressive type of tuberculosis in calves and in the sense that human tuberculosis 

 due to the bovine tubercle bacillus can infect calves the statement in the preceding 

 paragraph is true. With regard to the reciprocal infection of children by bovine 

 tuberculosis it may be pointed out that fourteen out of the twenty-seven cases of ali- 

 mentary tuberculosis investigated by the English Commission were due to bovine 

 tubercle bacilli.] Moreover, Eber produced an acute miliary tuberculosis with 

 tuberculous material from an adult human being suffering from pulmonary tubercu- 

 losis and tuberculous meningitis. [Probably an infection produced by the bovine 

 tubercle bacillus. See English Commission results, ante.] 



Such facts [may be considered to] constitute a sufficient basis for rejecting Koch's 

 hypothesis of the existence of two separate and distinct species of tubercle bacilli. 



E. Birds. 



(a) Birds are easily infected with the avian tubercle bacillus. Fowls may 

 be infected by any method of inoculation (sub-cutaneous, intra- venous, 

 feeding etc.), and the ingestion of cultures, infected tissues or other patho- 

 logical tuberculous products readily produces the disease. Post mortem 

 tubercles are found on the abdominal viscera but chiefly in the [spleen and] 

 liver. 



