SYMPTOMS 



305 



once gain lodgment, especially between the teeth, they are 

 removed only with difficulty. The favorite points for the act- 

 inomyces to enter the tongue is on the upper surface midway 

 between the dorsum and the tip. The lungs may be the seat 

 of primary infection due to the inhalation of the fungus. The 

 disease has been rarely observed primarily in the udder but 

 frequently in the subcutaneous tissue about the head. In man 

 the source of infection is more obscure. Many cases have 

 been reported where the individuals did not come in contact 

 with diseased animals and were not occupied in agricultural 

 pursuits or in handling grain but were glaziers, tailors and 

 various shop tenders. There are a few cases reported, how- 

 ever, where the circumstantial evidence points to direct infec- 

 tion from diseased animals. 



The present knowledge of this fungus indicates that it 

 must attain to a certain stage or period in its development 

 before it will live and multiply in living animal tissues. It 

 has been observed that, as a rule, cattle become infected when 

 they are kept upon dry food. 



§ 231. Symptoms. Actinomycosis is manifested by a 

 firm swelling or tumor usually situated in the region of the 

 head or throat. It is first recognized as a slight swelling of 

 the affected part resembling somewhat the result of a bruise. 

 It is stated by those who have had much experience with the 

 disease that many cases of actinomycosis seem to be caused by 

 blows or injuries received while struggling in stanchions. 

 The enlargement gradually increases in size. It is ordinarily 

 sharply defined from the surrounding tissues. 



Upon manipulation the tumor feels hard and dense. In 

 the region of the throat it may be fluctuating. After a 

 variable length of time, the ttimor-like mass may soften in one 

 or more places, rupture and discharge a rather thick, yellow- 

 ish and more or less sticky, purulent substance. The dis- 

 charge may continue or, as often happens, the opening heals 

 temporarily only to rupture again. The discharge often takes 

 place into the cavity of the mouth or throat. Sometimes the 



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