62 INFECTION AND IMMUNITY. 



life may remain latent until puberty and then, 

 when the unusual resistance which is coincident 

 with rapid growth has subsided, the bacilli mul- 

 tiply and tuberculosis manifests itself. He sup- 

 poses also that an intermediate generation may, 

 without showing tuberculosis itself, transmit the 

 disease to the next generation ( Ueberspringung von 

 Generationen) . This would seem to presuppose 

 the occurrence of germ-cell infection, but perhaps 

 not necessarily so. As having a possible bearing 

 on Baumgarten's hypothesis, it has been found by 

 Harbitz, by Wechselbaum and others that tubercle 

 bacilli, particularly in children, may exist in the 

 lymph glands without causing anatomical changes. 

 This view has several strong supporters, and it 

 is thought that the bacilli may remain latent in 

 any portion of the body. That hereditary syph- 

 ilis may remain latent for many years is well 

 known. 



On the other hand, it is more generally believed 

 that tuberculosis in most instances is a postnatal 

 acquisition (Koch, Cornet and others) and ra- 

 tional prophylaxis naturally must be based on this 

 conception. Extensive involvement of the liver 

 and periportal lymph glands is characteristic of 

 the placental transmission of tuberculosis. The be- 

 lief is occasionally expressed that leprosy may be 

 inherited, possibly through placental transmission, 

 but, in view of the non-susceptibility of animals 

 and failure to cultivate the bacillus, the question 

 cannot be taken up experimentally. The possibil- 

 ity of infection of the embryo directly from the 

 father during coitus is discussed, but there is no 

 definite proof of its occurrence. 



