INFLUENCE OF DISEASE UPON MILK 109 
the udder and is usually caused by the Bacillus phleg- 
masia tiberis or other varieties of colon bacilli, sometimes 
by organisms of the paracolon or paratyphus group, the 
enteriditis bacillus or by staphylococci. Septicemia may 
develop in the course of the disease. Severe cases may 
terminate in gangrenous mastitis. In the beginning of 
the disease, and throughout mild cases, a turbid fluid 
resembling whey in appearance and containing flakes of 
casein, is obtained from the affected quarter. Later, in 
cases of medium degree, the fluid resembles serum and 
contains clots of fibrin. In the more severe cases, the 
secretion is discolored with blood. In gangrenous mas- 
titis, a small amount of bloody-serous, dark, foul-smelling 
fluid, which contains gas bubbles, may be obtained from 
the affected quarter. The chemical changes which occur 
in the milk in parenchymatous mastitis are similar to those 
which take place in catarrhal mastitis. There is a de- 
crease in the lactose, which is sometimes entirely absent; 
the fat is usually decreased, although sometimes it is in- 
creased; the casein is decreased, while the albumin, glob- 
ulin, and salts, especially sodium chloride, are increased. 
The taste is salty or bitter. There is an increase in the 
content of catalase and coagulation takes place when the 
alcohol or boiling test is applied. 
3. Interstitial Mastitis——The simple, traumatic form 
of interstitial mastitis, in which the inflammatory process 
is limited in extent and rather mild, has no important 
effect upon the milk secretion, but when the disease is 
due to the entrance of bacteria through fissures or 
wounds, as is most frequently the case, a phlegmonous 
inflammation occurs in the subcutaneous or interstitial 
connective tissue which is accompanied by a rise of the 
body temperature, sometimes to 107° F-., and other symp- 
