SPIROCHJETA PALLIDA. 211 



stead of the sheep's corpuscles, as in the Wassermann test.) 

 These are washed in salt solution and used in a 1 per cent, 

 emulsion in salt solution, 1 c.c. being used. 



5. Aniboceptor against human blood-corpuscles. This is 

 obtained by the repeated injections of washed human blood- 

 corpuscles into rabbits, the serum being tested by titration 

 against human corpuscles. By reversing the above test 

 unknown antigen may be determined. 



Yaws. 



Castellan! in 1905 described a spirochsete closely resembling 

 Treponema pallida, which he found in cases of yaws. The 

 question of their identity or non-identity is still sub judice. 



Vincent's Angina. 



History. Vincent in 1896 described an inflammatory dis- 

 ease of the mouth, pharynx, and especially of the tonsils, 

 whose lesions resembled in appearance those of diphtheria, 

 the course of the disease, however, being much milder. 



Morphology. In the above-mentioned disease Vincent found 

 and described bacteria of two kinds, a fusiform or spindle- 

 shaped bacillus and a spirillum not unlike that of relapsing 

 fever in appearance. Some bacteriologists claim that these 

 differently shaped organisms are of a like nature, merely rep- 

 resenting different developmental stages of the same organism. 

 Others claim, however, that they represent distinct varieties 

 of organisms living in symbiosis. In length the fusiform 

 bacilli measure from 410 /JE, the spirilla from 612 //. The 

 spirilla have shallower, more rounded, and fewer curves than 

 the Treponema pallida. I have found a 1 : 10 carbol-fuchsin 

 solution the best stain. Ordinary blood stains and even 

 Loeffler's blue may be used ; Giemsa's blood stain gives 

 splendid results. An irregular intensity of the stain is a 

 characteristic of these bacteria. 



Pathogenesis. As mentioned above, these organisms are 

 found in inflammatory conditions of the mouth and pharynx, 



