SYPHILIS 605 



wider spiral, and stains deeper and more readily than the 

 latter. The S. pallidum is found generally in all primary 

 and secondary lesions of syphilis, e.g., the primary sore and 

 adjacent lymphatic glands, in the papular and roseolar 

 eruptions, in condylomata and mucous patches. It 

 has also occasionally been found in the spleen and blood. 

 In congenital syphilis the S. pallidum is met with in the 

 bullous eruptions, blood, and organs, and is particularly 

 abundant in the spleen and liver (Plate XXVI, 6). 



Tertiary lesions are generally considered to be non- 

 infective, unless ulcerated, and the S. pallidum is usually 

 difficult to find in them. It has, however, been detected 

 in the peripheral portions of gummata and in syphilitic 

 aortitis, and may persist in the body for years after the 

 primary lesion. Noguchi, after a careful search, has 

 detected the spirochaete in the brain in cases of general 

 paralysis (in 48 cases out of 200 examined) and also in 

 the posterior columns in a case of tabes. 



It must be recognised that spirochaetes are of frequent 

 occurrence in various non-syphilitic ulcerating and other 

 lesions, e.g. in the mouth and in pyorrhoea, in yaws and 

 ulcerating granuloma (in yaws they are specific forms ; see 

 p. 603), in ordinary ulcers and in carcinomatous tumours. 

 Generally the S. pallidum can be distinguished micro- 

 scopically from the other species, but care is necessary. 



Metchnikoff and Roux (also Griinbaum) found that the 

 chimpanzee is very susceptible to syphilis, and can readily 

 be inoculated from man, the S. pallidum being found in 

 the lesions. 



Macacus rhesus is also somewhat susceptible, likewise 

 the M . cynomolgus and the Chinese bonnet monkey, but 

 not the mandril. By several passages through a rhesus 

 monkey the syphilitic virus becomes attenuated, so that 

 in man it produces merely a local lesion. 1 Syphilis 



1 Metchnikoff, Journ. of Prev. Med., 1906, August. 



