586 PATHOGENIC ANAEROBIC BACILLI. 
prevails during the summer months in various parts of Europe, and 
is characterized by the appearance of irregular, emphysematous 
swellings of the subcutaneous tissue and muscles, especially over the 
quarters, hence the name “quarter evil.” The muscles in the 
affected areas have adark color and contain a bloody serum in 
which the bacillus is found. 
Morphology.—Bacilli with rounded ends, from three to five “ 
long and 0.5 to 0.6 4 broad ; sometimes united in pairs, but do not 
grow out into filaments. The spores are oval, somewhat flattened on 
one side, thicker than the bacilli, and lie near the middle of the rods, 
but a little nearer to one extremity. The bacilli containing spores 
are somewhat spindle-formed (Kitasato). ‘‘Involution forms” are 
quite common in old cultures or in unfavorable 
media ; in such cultures variously distorted and 
often greatly enlarged bacilli may be seen, some 
being greatly swollen in the middle — spindle- 
shaped. When properly stained, by Léffler’s 
method, a number of flagella are seen around the 
periphery of the cells. 
Stains with the aniline colors usually em- 
ployed, but not by Gram’s method. Spore-bear- 
ing bacilli may be double-stained by first stain- 
ing the spores by Ziehl’s method, and then the 
bacilli with a solution of methylene blue. 
Biological Characters.—An anaérobic, lig- 
uefying, motile bacillus. Forms spores. Grows 
at the room temperature in the usual culture media, 
in the absence of oxygen, in an atmosphere of hy- 
drogen, but not in carbon dioxide. This bacillus 
grows more rapidly and abundantly in nutrient 
agar or gelatin to which 1.5 to 2 per cent of 
grape sugar or five per cent of glycerin has been 
added. Colonies in gelatin, in an atmosphere of 
hydrogen, are at first spherical, with irregular out- 
lines and a wart-like surface ; later the gelatin is 
Fic. 160, Bacillus /iquefied around them, and radiating filaments 
‘of symptomatic an- grow out into the gelatin, so that by transmitted 
eee a ie light they present the appearance of an opaque 
tin, ten days at 18°- central mass with an irregular surface surrounded 
20°C, Kitasato.) by rays. In stab cultures in nutrient gelatin, at 
20° to 25° C., at the end of two or three days 
development occurs at the bottom of the line of puncture to within 
about two fingers’ breadth of the surface; the gelatin is slowly 
liquefied and considerable gas is formed. In old cultures the 
