32 SPIROCILETES. 



in a mixture of yolk of egg and decoction of mouse- 

 flesh for forty days. They observed the formation of 

 long chains under these conditions. Williams grew 

 this organism in defibrinated blood, and Norris, Pappen- 

 heimer and Flournoy cultivated Sp. obermeieri in cit- 

 rated blood. Lebailly states that Sp. pallida multiplied 

 when kept on pieces of infected liver, and Volpino and 

 Fontana found that it even grew into pieces of normal 

 liver placed in contact with the infected tissues. Bor- 

 rel and Burnet cultivated Sp. gallinarum in blood. 

 Levaditi cultivated Sp. pallida and also Sp. refringens 

 in collodion sacs placed inside the peritoneal cavities of 

 animals, but these cultures were not pure, being con- 

 taminated with great numbers of bacterial organisms. 

 Beer claims to have cultivated Sp. pallida, anaerobically 

 like a bacterium on bouillon mixed with ascitic fluid. 



Leuriaux and v. Geets state that they cultivated Sp. 

 pallida in a mixture of broth with cerebrospinal fluid 

 taken from syphilitic patients; after incubation in this 

 medium the precipitate formed was sown on pigs' se- 

 rum, and colonies developed. Other writers state that 

 they have obtained multiplication of these spirochaetes 

 by incubating portions of infected organs ; and Levaditi, 

 as previously mentioned, "cultivated" Sp. pallida in 

 collodion sacs within the peritoneal cavities of mon- 

 keys, but found the resulting "cultures" incapable of 

 inducing infection. 



Recently successful attempts to cultivate Sp. pallida 

 are reported by Schereschewsky and by Miihlens. The 

 medium used was horse-serum, which was first heated 

 to 58 to 60 C. a point at which it threatens to solidify 

 and then kept at 37 C. for three days. A piece of 

 infected tissue (e.g., a bit of a gland taken from a patient 

 suffering from syphilis) is then inserted deeply into the 

 medium and kept under anaerobic conditions for five 



