262 
N. COLIN. 
may undergo various modifications. It may continue to enlarge, 
it may raise itself, it may assume a color, either more marked or 
darker, it may become blueish in its whole extent or partially. 
There may be a dark, blackish circle at some distance from its 
opening. Its base may assume the aspect of a phlegmon or re¬ 
main cedematous; the ulceration of its summit may continue 
narrow and superficial, or may increase to such an extent as to 
destroy the skin and the surrounding sub-tissues to the extent of 
several square centimeters. But whatever may be its aspects, it 
runs its course in well defined steps. It has only a period of 
irritation and one of secretion, when it is to terminate by resolu 
tion, or otherwise; it has beside, a period of ulceration and one of 
suppuration, which may be of long duration. The malignant 
pustule of the dog differs then from that of man, in several par¬ 
ticulars. First, it develops more rapidly. It is very well formed 
in twenty-four hours after the inoculation, or in forty-eight 
hours, or at the most in three days. From the fourth or fifth 
day it is in a state of rapid resolution or it ulcerates and sup 
purates. In no case does it show an eschar which sloughs off in 
mass, nor a circle of phlyctenes round its summit. Its inflamma¬ 
tory character is always very high, and it terminates as often by 
resolution without loss of substance, as by ulceration and suppur¬ 
ation, In all cases, it has in common with that of man the pecu¬ 
liarity that it is' but little sensible or painful; that the oozing at 
the beginning is serous and remains so or nearly so to its end, if 
it is to be accompanied with general accidents or fatal complica¬ 
tions. It is in the fact of its possibly serious results that the 
malignant pustule of animnls differs from that of man. We 
know too well that in man, the pustule left to itself is inevitably 
followed by fatal results. It is even too probably and fre¬ 
quently so when subjected to the most judicious treatment. On 
the contrary, in the dog it is of a benignant character. It may 
reach enormous dimensions, may grow very rapidly and recover 
of itself, without any treatment. The dog may have two, four, 
six, even eight pustules, with oedema, without other symptoms 
than a little fever and loss of appetite, of short duration. This 
last essential difference is due to the fact that in the dog the car- 
