600 BACTERIOLOGY. 
hay, straw, or horse-manure, and it is doubtful whether 
it finds conditions in nature favorable to a saprophytic 
existence. It grows well in the incubating oven on 
glycerin-agar. Upon this medium at the end of twenty- 
four to forty-eight hours, whitish, transparent colonies 
are developed, which in six or seven days may attain a 
diameter of 7 or 8 mm. On blood-serum a moist, 
opaque, slimy layer develops, which is of a yellowish- 
brown tinge. The growth on cooked potato is especially 
characteristic. At the end of twenty-four to thirty-six 
hours at 37° C. a moist, yellow, transparent layer de- 
velops; this later becomes deeper in color, and finally 
takes on a reddish-brown color, and the potato about it 
acquires a greenish-yellow tint. In boulon it causes 
diffuse clouding, with ultimately the formation of a 
more or less ropy tenacious sediment. Milk is coagu- 
lated with the production of acid. It grows on media 
possessing an acid reaction, and both with and without 
oxygen. 
Pathogenesis. The bacillus of glanders is pathogenic 
for a number of animals. Among those which are most 
susceptible are horses, asses, guinea-pigs, cats, dogs, 
ferrets, moles, and field mice; sheep, goats, swine, rab- 
bits, white mice, and house mice are much less suscep- 
tible; cattle are immune. Man is susceptible, and in- 
fection not infrequently terminates fatally. 
When pure cultures of the bacillus mallei are injected 
into horses and other susceptible animals true glanders 
is produced. The disease is characterized in the horse 
by the formation of ulcers upon the nasal mucous mem- 
brane, which have irregular, thickened margins, and 
secrete a thin, virulent mucus; the submaxillary lym- 
phatic glands become enlarged and form a tumor, which 
