ON SPECIFIC THERAPEUTICS. 61 



syphilis. It will be more correct to imagine 

 that the delicate spirochaetae have lost their 

 power of infecting because they have found no 

 suitable nutritive bodies in the serum. 



On the other hand we know, from the funda- 

 mental experiments of Metchnikoff and Roux, 

 that typical primary lesions can in apes be 

 obtained in any part of the skin, in the lower 

 monkeys chiefly in the eyebrows and penis. 

 Infection could also be produced by rubbing 

 diseased tissue on to the cut surface of the 

 testicle. On examining the inner organs of the 

 monkeys, Neisser found the virus to be present 

 only in a few organs, especially the haemato- 

 poietic organs, viz., the spleen, the bone mar- 

 row and the lymphatic glands, as well as in the 

 testicles, whilst all the other organs proved 

 sterile. For this reason Neisser thought that 

 the primary processes in certain denned tissues 

 were of importance for the occurrence of the 

 generalised disease. If we follow this view, it 

 will be most easy to explain the state of affairs 

 by the hypothesis that the serum of monkeys 

 does not contain properties sufficient for the 

 nutrition of the spirochaetae, whilst in certain 

 cells of these animals, viz., the epithelia, the 

 testicular cells and the leucogenic cells, sub- 



