606 TREPONEMATA, SP I RON EM AT A, LEPTOSPIRATA 
to develop long tangled filaments in which granules may be absent. 
Motility has not been observed, and spores and capsules have never 
been demonstrated. Ordinary stains color the organisms faintly, 
but stains containing mordants, as carbol-fuchsin and carbol-thionin, 
stain them readily and one or two intensely colored granules are fre- 
quently observed in each organism. The organisms are Gram- 
negative. 
Tunnicliff^ obtained development of fusiform bacilli in ascitic fluid 
media (anaerobic) at 37° C, but subcultures were usually negative. 
Krumwiede and Pratt,^ using an improved anaerobic culture method, 
obtained pure cultures in anaerobic ascitic agar or serum agar from 
a variety of lesions of the type mentioned above. The colonies were 
small, more or less circular in outline with projecting, hair-like growths, 
which attain a diameter of 1 to 2 mm. In all, fifteen strains were 
isolated in pure culture, all of which produced indol and possessed a 
disagreeable odor. Two distinct cultural types were distinguished; 
all strains produced acid, but no gas, in glucose, galactose and levu- 
lose; one type produced acid in saccharose, the other type was with- 
out action upon this sugar. There was no demonstrable relation 
between the source of the culture and the fermentation of saccharose, 
which is in harmony with TunnicliflF's observation that the fusiform 
bacilli obtained from a variety of lesions presented no demonstrable 
distinctive characters. 
No spiral organisms developed in the cultures, although they were 
present in smears from the original material. This points strongly 
to the non-identity of the fusiform bacillus and the spiral organism 
so frequently associated with it, although Tunnicliff^ claims that the 
spirilla and the fusiform bacilli are different forms of a single organism. 
Recently Varney^ has isolated many cultures of fusiform bacilli, none 
of which have ever contained spiral organisms. The fusiform organ- 
isms are divisible into at least four types of rather distinctive and 
constant morphology, which show serological differentiation by agglu- 
tination tests. 
The relation of the fusiform bacilli to morbid processes is not finally 
established, although the injection of material rich in these organisms 
has frequently led to necrosis and suppuration in experimental animals. 
The most convincing evidence of their pathogenicity is the occasional 
demonstration of fusiform bacilli in considerable numbers in tissues 
from cases of noma and similar severe lesions. 
1 Jour. Infec. Dis., 1906, 3, 148. 
2 Ibid., 1913, 12, 199; 13, 438. 
= Ibid., 1911, 8, 316. 
* Jour. Bacteriol., 1927, 13, 275. 
