520 SYPHILIS 



organism which may be present in a well-preserved condition 

 in macerated foetuses render it probable that the Organism may 

 multiply in the dead tissues under anaerobic conditions. 



Cultivation. — Although Miihlens and Hoffmann had previously 

 obtained pure cultures of an organism morphologically identical 

 with the spirochaete pallida, it is chiefly to Noguchi that we owe 

 the methods of cultivation. We shall accordingly state his 

 results, which in certain respects differ from those of the other 

 two observers. In the first instance his cultures were made 

 from syphilitic lesions in the rabbit, but later directly from the 

 lesions of the human disease. As a culture medium he used a 

 mixture of two parts of 2 per cent, agar and one part of ascitic 

 or hydrocele fluid, to which a small portion of sterile rabbit's 

 kidney or other organ was added, the medium being placed in 

 deep tubes and covered with a thick layer of paraffin oil. The 

 medium was inoculated through the oil, the maintenance of strict 

 anaerobiosis being essential. When contaminating bacteria were 

 present these formed a thick growth along the line of inoculation, 

 whilst the spirochetes grew as a diffuse haze into the surround- 

 ing medium. By making sub-cultures from parts apparently free 

 from bacterial growth he succeeded in obtaining the organism in 

 the pure condition. At first the organisms were small, but after 

 several days they had the usual length of the spirochete pallida 

 and all its characteristics. An important point is that he found 

 clear evidence that the organism multiplies by longitudinal 

 division. On inoculating monkeys {macacus and cercopithecus) 

 by scarification, in some cases indurated syphilitic papules 

 developed and the blood of the animals gave a positive 

 Wassermann reaction. The etiological relation of the organ- 

 ism has thus been completely established. 



Transmission of the Disease to Animals. — Although various 

 experiments had previously been made from time to time by 

 different observers, in some cases with reported successful result, 

 it is to the papers of Metchnikoff and Eoux (1903-5) that we 

 owe most of our knowledge. These observers carried on a 

 large series of observations, and showed that the disease can 

 be transmitted to various species of monkey. Of those the 

 anthropoid apes are most susceptible, the chimpanzee being the 

 most suitable for experimental purposes. Their results have 

 been confirmed by Lassar, Neisser, Kraus, and others. The 

 number of experiments on these animals is now very great, and 

 the general result is that the disease has been transmitted by 

 material from all the kinds of syphilitic lesions in which spiro- 

 chsetes have been demonstrated, including tertiary- lesions and 



