TUBERCULOSIS. 269 



the bacilli. Tuberculosis pursues a more rapid course in 

 youth than at a later age, and experimentally no difference 

 can be observed between young and old animals. On the 

 other hand, Gartner is of the opinion that in the act of par- 

 turition, perhaps in consequence of tears in the placenta, 

 the bacilli pass over from the mother to the child. The 

 possibility of such a transfer of the tubercle-bacilli to the 

 embryo Gartner has himself demonstrated with certainty 

 in his experiments upon mice, canary-birds, and rabbits. 

 Fetal infection, according to this view, takes place late, and 

 in all probability it is effected through only one or a few 

 bacilli. Consequently, the disease can not be manifest at 

 birth, but it becomes evident only after the child has lived 

 for some time outside the uterus. Also, the cases of pri- 

 mary tuberculosis of the skin, the joints, the bones, the 

 glands, the spleen, the liver, which are not uncommon in 

 early childhood, indicate a hematogenous fetal infection. 

 The objection that the frequency of pulmonary tuberculosis 

 is opposed to the preponderant occurrence of hematog- 

 enous fetal transmission, is, according to Gartner, justified ; 

 but it is to be borne in mind that, in spite of exhibiting the 

 most conspicuous changes, the lungs are by no means 

 always the seat of the primary tuberculous lesion. The 

 lungs of human beings are, "by reason of their constitu- 

 tion, their situation, and their chemistry, especially adapted 

 for the lodgment and development of tubercle-bacilli," 

 which may gain entrance from any primary focus (perhaps 

 of fetal origin). The question whether tuberculosis may 

 be transmitted to the embryo from the father Gartner an- 

 swers in the negative. He rendered male rabbits and 

 guinea-pigs tuberculous by injection of bacilli into the tes- 

 ticles, and he then brought them in contact with females, 

 but the offspring were not tuberculous ; whereas when the 

 bacilli were present in the seminal fluid in considerable 

 numbers, the females were infected. 



Therapeutic Experiments. Many efforts have been 

 made to confer immunity to tuberculosis, and to effect the 

 cure of tuberculosis by the same means. This end was 

 sought by the use of the blood-scrum of animals that are 

 relatively refractory to the disease, such as dogs (Richet and 

 Hericourt) and goats. Further, attempts have been made 

 to establish immunity by means of attenuated or sterilized 

 cultures of tubercle-bacilli. All of these endeavors, how- 



