SPIROCH^TiE 387 



without any growth of spirochetes, at two points on the right 

 arm. Local inflammation on the left arm, appearing in two to 

 ten days and sometimes resulting in the formation of a pustule, is 

 regarded as a positive test. The test is often negative in the 

 earUer stages of syphilis. 



The various diagnostic tests for syphilis are now extensively 

 employed. Microscopic search for the spirochete is of value in the 

 untreated primary and secondary stages. The complement-fixa- 

 tion test becomes positive a few weeks after the appearance of, the 

 primary lesion and is generally regarded as indicating an active 

 syphilitic process. The luetin test may be positive in latent or 

 inactive syphilis when the Wassermann is negative. Further 

 experience with the luetin test is necessary in order to determine 

 its real significance. . 



SpirocHaeta (Treponema) Refringens. — This is a relatively 

 gross spirochete which occurs in primary syphilitic lesions along 

 with Sp. pallida. It seems to have no pathogenic properties. 

 Noguchi^ has obtained pure cultures of it and found them with- 

 out pathogenic properties for rabbits and monkeys. 



Spirochaeta (Treponema) Microdentium.^^ — This is one of the 

 common spirals of the mouth. It may be confused with Sp. pal- 

 lida, which it resembles in size and shape. Pure cultures have 

 been obtained by Noguchi. Other spirochetes of the mouth 

 have also been cultivated by this investigator and there are prob- 

 ably several species of them. 



^ Journ.'Exp. Med., 1902., Vol. XV, p. 466. 

 ''Noguchi: Journ. Exp. Med., Vol. XV, pp. 81-89. 



