112 SPIROCELETES. 



SPIROCH^ETA PERTENUIS. 



(Castellani, 1905.) 

 (Spirochaeta pallidula, Castellani, 1905.) 



Castellani found spirochaetes present in eleven out of 

 fourteen cases of the disease called yaws, framboesia, 

 or pian; and the discovery was confirmed by other 

 observers (Borne, Schiiffner, etc.). The organisms 

 are very slender, and vary in length from a few microns 

 up to 1 8 or 20 p.. Their extremities are pointed as a 

 rule, though some individuals appear to have blunt ends. 

 Their curls are numerous and symmetrical, but some- 

 times part of the organism may appear straight (Fig. 

 89). Nodules may be visible at their extremities, and 



FIG. 89. Spirochaeta pertenuis. (Castellani.) 



also in their length (Fig. 21). Ovoid bodies were also 

 found by Castellani (5 to 8/t by 4 to 6/*) and were 

 thought by him to be possibly a stage in the develop- 

 ment of the spirochaetes; they were very rare. 



Monkeys were inoculated with the spirochaetes, and 

 the organisms were found in the resulting lesions. 

 Monkeys thus inoculated showed no immunity to 

 syphilis; this is held to prove the two diseases to be 

 different. 



These spirochaetes are almost exactly like Sp. pallida, 

 especially when stained with silver by Levaditi's 

 method; but Mclntosh states that the positions they 

 respectively occupy in the lesions are different (see page 



