DISEASES CAUSED BY SPIROCHiETES 613 



deeply stained near the end, and showing a banded or striped alternation 

 of stained and unstained areas in the central body. Their staining 

 qualities in this respect are not unlike those of the diphtheria bacillus, 

 and according to Babes ' the dark areas are to be interpreted as meta- 

 chromatic granules. The bacilli are not motile. 



The spirilla found in Vincent's angina are usually somewhat longer 

 than the fusiform bacilli, and are made up of a variable number of un- 

 dulations, shallow and irregular in their curvatures, unlike the more 

 regularly steep waves of Spirochseta pallida. They are stained with 

 even more difficulty than are the bacilli and usually appear less distinct 

 in the preparations. The stain, however, is taken without irregu- 

 larity, showing none of the apparent metachromatism observed in the 

 bacilli. 



By the eariier observers cultivation of these microorganisms was 

 attempted without success. Recently, however, it has been shown that 

 cultivation could be carried out under anaerobic conditions. Tunni- 

 cliff ^ has cultivated the organisms anaerobically upon slants of ascitic 

 agar at 37.5° C. This observer found that in such cultures, before the 

 fifth day, bacilli only could be found, that after this time, however, 

 spirilla gradually appeared and finally constituted the majority of the 

 organisms in the culture. It appeared, to Tunnicliff from this study 

 that the spirilla might be developed out of the fusiform microorgan- 

 isms representing the adult form. 



The microorganisms of Vincent's angina, when occurring in the 

 throat, are rarely present alone, being usually accompanied by other 

 microorganisms, such as staphylococci, streptococci, and not infre- 

 quently diphtheria bacilli. When occurring together with diphtheria, 

 they are said, by some German observers, to aggravate the latter 

 condition considerably. This frequent association with other micro- 

 organisms renders it impossible to decide conclusively that the fusi- 

 form bacilli and spirilla are the primary etiological factors in these 

 inflammations. It has been frequently suggested that they may be 

 present as secondary invaders upon the soil prepared for them by other 

 microorganisms. 



Animal inoculation with these microorganisms has led to little result. 



Fusiform Bacilli other than those in Vincent's Angina. — Fusiform 

 bacilli morphologically indistinguishable from those found in the angina 

 of Vincent may frequently be found in smears taken from the gums, 



' Babes, in Kolle und Wassermann, 1. Ergiinzungsband, 1907. 

 ' Tunnicliff, Jour, of Infec. Dis., 3, 1908. 



