858 PATHOGENIC MICROORGANISMS 



Soon after the experiments of Metchnikoff and Roux, successful 

 inoculations upon lower monkeys (macacus) were carried out by 

 Nicolle. 29 Since that time, it has been found by various observers 

 that almost all species of monkeys are susceptible. Simple sub- 

 cutaneous injection is not sufficient to produce a lesion. The tech- 

 nique which has given the most satisfactory results consists in the 

 cutaneous implantation of small quantities of syphilitic tissue ob- 

 tained by excision or curetting of primary and secondary lesions. A 

 small pocket is made under the mucous membrane of the genitals 

 or of the 'eyebrows and the tissue placed in this under aseptic 

 precautions. The inoculation may be made directly from the human 

 being, but can also be successfully carried out from monkey to 

 monkey for many generations. Attempts at transmission from ter- 

 tiary lesions have so far been unsuccessful. The spirochaetes can 

 be demonstrated both in the primary lesions of the inoculated animal 

 and in the secondarily enlarged glands. The successful inoculation 

 of rabbits with syphilis has been recently performed by Bertarelli. 30 

 He obtained ulcerative lesions by inoculation upon the cornea and 

 into, the anterior chamber of the eye and was able to prove the 

 syphilitic nature of these lesions by finding the spirochaete within 

 the tissue. In these animals, as well as in the lower monkeys, the 

 disease usually remains localized. 



In 1907 Parodi showed that syphilitic lesions could be produced 

 by direct inoculation into the testicles of rabbits. This method of 

 inoculation has been subsequently studied by many investigators, 

 especially by Uhlenhuth and Mulzer. 31 It is the easiest method of 

 obtaining spirochaete in any quantity from lesions in man. The 

 spirochaate-containing lesions may be either excised or scraped as 

 conditions permit and rubbed up in a mortar with sterile sand, 

 in a few centimeters of sterile human ascitic fluid. This emulsion 

 is then injected directly into the substance of rabbit testicles. A 

 swelling supervenes which is often noticeable after two weeks, and 

 is usually at its height in five to seven weeks. At this time the 

 testicle is much larger than normal, sometimes evenly swollen and 

 sometimes nodular, and of a firm elastic consistency. When taken 

 out at castration it oo/es a sticky fluid, both from testicle and 

 tunica, which is rich in actively motile spirochaetes. By continuous 



29 Nicollr, Ann. do 1'inst. Pasteur, 1903. 



30 Bertarelli, Cent. f. Bakt., xli, 1906. 



n Uhlenhuth und Mulzer, Arb. a. d. k. Gesimdh't's Amt., xxxiii, 1909. 



