ELEVENTH ANNUAL REPORT. 139 
man. Among wild animals in captivity we have seen the disease 
in mule deer, Florida deer, prong-horned antelope, and in a 
grizzly bear. Experimentally, the disease has been produced in 
calves, dogs, goats, and guinea-pigs. The disease now recog- 
nized as actinomycosis has long been known to stockmen and 
veterinarians as “lumpy jaw,’ “wooden tongue,” cancer of the 
tongue, etc., but it was not until 1876 that its true pathology was 
demonstrated by Bollinger. When he had identified and accu- 
rately described the pathogenic organism, new observations of the 
disease were rapidly made, not only in animals but in man. 
Studies of the last few years appear to have established the fact 
that there are a number of closely allied organisms belonging to 
the group of actinomyces “ray fungus,” and that the clinical 
phenomena ordinarily called actinomycosis may be due to any one 
of several closely allied parasites. All of the actinomyces are 
branching fungi, non-motile and spore-forming. 
As a rule the disease appears sporadically. It may, however, 
attain an enzootic distribution. It is quite widely distributed in 
the temperate zones, but has not yet been recognized to any extent 
in the tropics. 
The disease as seen in wild animals is especially virulent, runs 
a very acute course, and is invariably fatal. In this respect it 
differs from the affection as seen in the domestic animals, where 
it generally assumes the chronic form, and where the treatment 
with iodide of potassium is followed by marked improvement. 
The “ray fungus” may, under certain circumstances, exhibit a 
general distribution. We have observed several cases of general- 
ized actinomycosis—prong-horned antelope and bear—with me- 
tastases in the cervical lymph nodes, stomach, diaphragm and liver. 
Cause.—The cause of actinomycosis is the propagation in the 
tissues of the actinomyces, or “ray fungus.” This fungus is 
supposed to grow especially on cereals, particularly barley, the 
beards of which favor its entrance into wounds of the skin and 
mucous membranes of the mouth; but since the disease is of 
frequent occurrence on our western ranges, where the cereals do 
not exist, it would seem that it must be traced to other forms of 
graminez, or to diverse vegetation and soil. 
The period of dentition and the attendant laceration of the 
gums affords good opportunity for the entrance of the fungus; 
hence, youth is a strongly predisposing condition. The winter 
season is the main period of invasion, the dry, fibrous fodder 
tending to scratch or wound the mucous membranes of the gums, 
cheeks, and tongue, and thus open a portal of entry for the para- 
