DISEASES CAUSED BY SPIROCH^TES 859 



transinoenlation from one rabbit to another such a strain can be 

 indefinitely carried along. It can be inoculated from rabbits to 

 monkeys and vice versa. This method as well as Noguchi's cultiva- 

 tions have opened a new era of spirochaete investigation. It is 

 stated by some observers that intravenous inoculation of rabbits 

 may be followed by localization in the testis and occasionally gum- 

 matous infections in other parts of the body have been induced 

 after such inoculation by Uhlenhuth, Mulzer, and others. Brown 

 and Pearce in an elaborate series of recent investigations published 

 in Journal of Experimental Medicine in 1920, have succeeded in 

 reproducing almost all types of syphilitic lesions in rabbits by 

 appropriate methods of inoculation. 



Immunization in Syphilis. It is a well-known fact observed by 

 clinicians that during active syphilis the patient cannot be superin- 

 fected. That this resistance develops quite rapidly was shown by 

 Metchnikoff and Roux, who found that reinfection of a monkey was 

 possible if attempted within two weeks of the first inoculation, but 

 was unsuccessful if delayed beyond this period. 



On the basis of this knowledge, Metchnikoff, 32 Finger and Land- 

 steiner, 33 and others have made attempts to devise some method of 

 immunization. They attempted to attenuate the syphilitic virus 

 by repeated passage through monkeys. These experiments were 

 unsuccessful, the last-mentioned observers finding absolutely no at- 

 tenuation after twelve generations of monkey inoculation. 



Bertarelli and others have shown that the production of a 

 syphilitic lesion on the cornea of one eye does not protect against 

 an inoculation done on the other. Rabbits that have been inoculated 

 with spirochaete material and that have not developed syphilitic dis- 

 ease can be successfully inoculated on subsequent attempts. The 

 offspring of female rabbits with syphilis of the cornea are, according 

 to Muhlens, not immune. 



There is no evidence so far that specific therapy or treatment 

 with spirochaete material has had favorable influence upon the disease. 

 Chemotherapy has had results analogous to those obtained in man. 34 



Attempts at passive immunization have been entirely without 

 success. 



8 * Metchnikoff, Arch. gen. de m6d., 1905. 



33 Finger und Landsteiner, Sitzungsber. d. Wien. Akad. d. Wiss., 1905. 



34 Von Prowazelc, "Handbuch der pathogenen Protozoen," i, 1912, Leipzig, 

 Bartsch. 



