UDDER-PYOBACILLOSIS 75 



mal. The quarter was not changed. The quantity of milk 

 was not diminished. The milk had a normal appearance 

 but presented a small quantity of sediment composed of 

 cells. The cells contained one single bacillus pyogenes. 



On the third day after infection the quarter was un- 

 changed. The milk was unaltered. 



The same conditions obtained on the following day. 



Nine days after the infection the part near and behind 

 the teat (this was a hind quarter that was infected) was 

 swollen and presented a distinctly circumscribed round, 

 hard, sensitive swelling the size of a hen's egg. The milk 

 was not changed. 



This condition was the same on the following day. 



Seventeen days after the infection the skin of this part 

 of the udder was oedematously swollen, firm and immovable 

 and adhered to the swelling of the udder. The milk was 

 yellow and flocculent and contained a moderate sediment 

 which consisted of pus containing groups of bacillus 

 pyogenes. 



Twenty-one days after the infection this condition re- 

 mained the same. The animal was then slaughtered. 



Autopsy. — The infected quarter was swollen and firm 

 around the base of the teat. The incision was purulent. 

 The lower part of the cut surface even, gray and firm. The 

 lobuli showed no milk points, but instead small pus points 

 up to the size of a pinhead. Upon pressure yellow plugs 

 of pus were expressed. Externally at the upper part of 

 and behind the base of the teat there was a cavity the size 

 of a walnut with thick connective-tissue wall and irregular 

 lumpy interior. It contained a greenish-yellow, thick pus 

 which showed large numbers of small fine Gram positive 

 pyogenes bacilli. 



2. Three weeks after parturition another milch cow 

 was injected in one teat with 10 c.c. of a mixture con- 

 sisting of equal parts of bouillon culture of streptococci and 



