METHODS AND CHANNELS OF INFECTION. 531 



the infecting agent is carried in the circulation to the kidney although it 

 occasionally ascends through the urethra from without. 



In conclusion, the proposition of germinal and antenatal infection 

 must be mentioned. By true germinal infection is meant the carrying 

 of the infectious microorganisms of a disease by the ovum or the sperma- 

 tozoon and its incorporation in the development of the embryo and foetus. 

 It is doubtful if this ever occurs. Some authorities claim that it is possible 

 and that it has been demonstrated that the spermatozoa may carry the 

 Treponema pallidum, of syphilis, but this is not generally accepted. 

 Antenatal infection or infection of the foetus before birth does occur. 

 Infectious microorganisms enter the fcetus only from the mother and it 

 has been repeatedly shown that tuberculosis and syphilis may be acquired 

 in this way. It is essential, however, that the mother be infected and, in 

 most instances, this infection is localized in the placenta. Smallpox, 

 scarlet fever, measles, dysentery, various pyogenic infections and in 

 rare instances pneumonia have been acquired by placental infection. In 

 rare cases in animals, anthrax, symptomatic anthrax, chicken cholera, 

 and glanders have been acquired by antenatal infection from the mother. 

 The extent of such transmission cannot be easily determined on account 

 of the close relationship of the mother and the possibility of other means 

 of transmission occurring. 



VARIATION IN INFECTION. 



There may be a variation in the infection depending upon the 

 route by which the infectious microorganism enters the body. For 

 example, in the case of Bact. tuberculosis, if the bacterium enters the 

 skin, a non-fatal infection, called lupus, results; if it enters the lymph 

 glands or joints and localizes there an inflammation of not necessarily 

 a fatal character results; if it enters the lungs, pulmonary tubercu- 

 losis or consumption which usually, after being well established, runs 

 a fatal course; if it enters the intestine, intestinal tuberculosis may 

 result, which is nearly always fatal, and if it enters the meninges, tubercu- 

 lar meningitis results which is rapidly fatal. Just so with the Strept. 

 pyogenes, depending on whether it enters the circulation, the lymphatic 

 vessels of the skin, or the connective tissues, there results septicaemia, 

 erysipelas, or abscesses, which obviously differ in their severity. The 

 same is true of practically all the pathogenic bacteria which invade the 



