ELEVENTH ANNUAL REPORT. 139 



man. Among wild animals in captivity we have seen the disease 

 in init/c 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 

 difters 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 

 gramineae, 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- 



