UDDER-ACTINOMYCOSIS 109 



the blood-stream. I have never seen the infection produced 

 through an udder-wound. 



An infection through the blood-stream always follows 

 actinomycosis of the lungs. This disease is rare, however, 

 perhaps less frequent than actinomycosis of the udder. 

 Therefore I maintain that this portal of entry does not 

 play so great a role since I know of no positive case of 

 actinomycosis of the lungs and udder together. 



The most important port of infection is the teat canal. 

 Of seven actinomycotic udders sent to the Veterinary High 

 School three of the cases were reported to have shown no 

 alterations in the lungs. Lung tuberculosis was observed 

 in one case and in the three other cases no report was made 

 concerning the lungs. None of the udders presented 

 wounds. 



Of four cases with complete history, therefore, three 

 were positively primary udder-actinomycosis through teat 

 infection. In the fourth case it may be possible that actino- 

 mycosis was also present with the tuberculosis but was 

 overlooked by the veterinary inspector. This case is there- 

 fore probably, but not positively, primary udder-actinomy- 

 cosis through teat-infection. 



It is not to be thought that the slowly growing actino- 

 myces fungus develops in the milk in the teat canal, but 

 one must admit, on the contrary, that the organism is 

 mechanically forced into the teat canal on a straw. 



Local Conditions. — Leucocytes pick up the fungus 

 and deposit it in the lymph spaces of the stroma, where the 

 fungus finally destroys the leucocytes. 



Primary Lesion and Inflammation. — The fungus 

 paralyzes and necrotizes the leucocytes which have engulfed 

 it and this cell necrosis constitutes the primary lesion. 



A great number of cells emigrate and collect around 

 the primary lesion (emigratory stage of inflammation), 

 and outside this wall of leucocytes a capsule of new con- 



