516 TREPONEMATA AND SPIROCHETA 



tion of the organisms there. Schereschewsky 1 grew the organisms 

 in impure culture in anaerobic cultures of gelatinized horse serum, 

 that is, horse serum which has been heated to 60 C. for some hours. 

 To Noguchi, however, 2 belongs the credit of obtaining Treponema 

 pallidum in pure culture, and of demonstrating its etiological rela- 

 tionship to the disease syphilis. 



The medium which gave the best results is prepared in the following 

 manner: Two per cent, slightly alkaline agar is melted and quickly 

 cooled to 45 to 50 C. and sterile ascitic or hydrocele fluid is added 

 in the proportion of two parts of agar to one part of fluid. At the same 

 time a small piece of sterile tissue from a rabbit's testis or kidney is 

 introduced. The medium is rapidly cooled to room temperature and 



FIG. 74. Treponema pallidum. 



covered with a layer of sterile paraffin oil, 2 to 3 c.c. deep, to keep 

 out the air. The medium is incubated for two days to ensure sterility 

 and is then inoculated with appropriate material, after first being 

 .certain that the material contained the organisms. The syphilitic 

 tissue, prior to inoculation, is macerated under sterile conditions 

 with 1 per cent, sodium citrate solution and then introduced deeply 

 into the agar-ascitic fluid-tissue media. Incubation is maintained at 

 37 C. for two to three weeks. The Treponemata in virtue of their 

 motility move away from the line of inoculation and cause a more 

 or less uniform, faint clouding of the medium. The associated con- 

 taminating organisms are for the most part confined chiefly to the 

 line of inoculation. At the end of the period of incubation the tube 



1 Deutsch. med. Wchnschr., 1909, xxxv, 835, 1260. 



2 Jour. Am. Med. Assn., 1911, xvii, 1.02; Jour. Exp. Med., 1912, xv, 90. 



