GENERAL CHARACTERS OF SPIROCILETES. 53 



spirochsete of yaws (Sp. pertenuis) is indistinguishable 

 from Sp. pallida. So far as the silver- stained prepara- 

 tions made by Levaditi, for example, are concerned, 

 this is true. (On the other hand, Sp. pertenuis as de- 

 picted by Castellani is different in appearance from Sp. 

 pallida, not showing the same regular curls.) If then 

 we have in yaws an organism exactly resembling Sp. 

 pallida, the argument that this organism is only found 

 in syphilis would seem to break down, since Sp. pallida 

 is only recognised by its morphological characters. 

 The identity of form is noted by Beurman and 

 Gougerot, by Levaditi and Nattan-Larrier, by Schiiffner 

 and by Wellmann, and was admitted by Schaudinn 

 himself. 



6. Levaditi succeeded in cultivating Sp. pallida (i.e., 

 in causing some multiplication of the organisms and 

 keeping them alive) in collodion sacs placed within the 

 peritoneal cavities of monkeys. These cultures failed 

 to produce infection when inoculated in other monkeys 

 susceptible to syphilitic infection. The negative result 

 is not perhaps in itself a very strong argument against 

 the causality of the spirochaete, as the organism may 

 easily have become attenuated by this procedure. 

 Nevertheless it may be pointed out that Levaditi allows 

 that a similar failure in the case of the spirochaete of 

 balanitis is evidence against the causal connection of 

 this organism with this disease, and the argument is as 

 strong in one case as in the other. A positive result 

 from inoculation of a culture has since been recorded 

 by Bruckner and Galacesco. 



7. The argument derived from the destructive and 

 agglutinating action of the serum of syphilitic pa- 

 tients on the Spiroch&ta pallida is somewhat weakened 

 by the fact that De Lisle and Jullien 1 found a coccus in 



1 La Semaine Medicate, 1900, page 279. 



