Pathogenic 3ficrobes in the Static Condition. 53 



takes place between two subjects independent of each 

 other (direct contact), or from the mother to the foetus 

 (heredity). 



Direct contact. — Direct contact seems to be necessary 

 for a certain number of diseases: rabies (bites), syph- 

 - ihs, dourine (coition), in which the germs, conta- 

 gious obligatory parasities, appear not to maintain 

 their virulence in the surrounding media. On the 

 contrarj^, in other diseases direct contact is not essen- 

 tial, the microbes maintaining their virulence outside 

 of the organism : glanders, tuberculosis, charbon, etc. 



Man becomes infected by direct contact when he 

 accidentally inoculates himself in making autopsy on 

 bodies affected with glanders, tuberculosis or charbon. 



Heredity. — 'Contagious diseases appear to be trans- 

 mitted from the mother to the foetus only by passage 

 of the specific microbes through the placenta. The 

 intervention of the father in phenomena of this kind 

 is therefore indirect, in as much as the disease with 

 which he is affected must first be transmitted to the 

 mother, a fact which is observed in syphilis, for ex- 

 ample. Here, therefore, the action of the mother in 

 reality alone comes into play. 



Some infectious diseases are transmitted from the 

 mother to the foetus; these are especially general af- 

 fections and those in which the germs are able to cir- 

 culate in the blood : certain septicsemias, charbon, 

 fowl-cholera, strangles, rouget, tuberculosis. 



The transmission seems to occur through alterations 

 of the placenta, such as hemorrhages, specific lesions 

 (tubercles, etc.), alterations which, indeed, are readily 

 produced on account of the diseased condition of the 



