2 



Scientific Proceedings (77). 



nodules are produced in the testicle by the thicker forms in five 

 to six weeks. With the thinner types, however, the incubation 

 period is briefer and in ten to fourteen days the testicle becomes 

 swollen, gradually resulting in a large diffuse lesion. 



In reference to the investigations which have been made with 

 strains from the nervous system, it is interesting to note that 

 recently Zinsser has obtained contradictory results to those of 

 Nichols with the identical strain sent him by Nichols. Wile's 

 work with cultures of his strain seem to support the results of 

 Zinsser. 



Rabbits were inoculated with material from the brains after 

 death of seven cases of parenchymatous syphilis, and we have 

 succeeded in obtaining strains in four cases. 



Two of these strains were lost after the second generation, 

 but of the two remaining, we have been able to continue one to 

 the seventh and the other to the ninth generation. Although 

 these strains have not passed through so many generations, 

 lesions have occurred in a sufficient number of rabbits of each 

 generation to afford some interesting deductions. In reference to 

 the percentage of takes, there has been a slight variation in the 

 two strains studied. While one of the strains has produced 

 lesions in eighty to ninety per cent, of the rabbits inoculated, 

 the other has shown a fluctuation between seventy and one 

 hundred per cent. The incubation periods have likewise exhibited 

 some irregularity. So far they have varied from sixteen to sixty- 

 seven days, but have averaged from nineteen to thirty-one days. 

 Neither of the strains have shown any distinctive features in 

 regards to the incubation time. The character of the lesions has 

 constituted a factor of considerable significance, in that both 

 hard nodules and large diffuse processes have been obtained. 



With one of the strains, a majority of the lesions which 

 developed were of the large diffuse variety. It is apparent that 

 in this instance most of the lesions have corresponded to those 

 produced by the so-called thinner forms of treponemata. 



The inference seems justifiable, from the work of our laboratory 

 extending over a considerable period of time, that the strains of 

 treponemata designated by Noguchi as the thinner types appear 

 to play as important a r61e in parenchymatous syphilis of the 

 nervous system as the thicker ones. 



