810 
W. L. WILLIAMS. 
broad sense transmissible, but we find outbreaks of mammitis, 
especially in ruminants, which are known as contagious or in¬ 
fectious mammitis and which at times become enzootic over a 
wide area and cause severe losses to stock owners, besides ren¬ 
dering questionable the wholesomeness of the milk supply. In 
any of the foregoing cases there is no essential bar to transmis¬ 
sion from one animal to another, and frequently we note clini¬ 
cally the extension of mammitis from one quarter or half to 
another, evidently by the same but more concentrated means by 
which it could be carried further to other animals either near 
or remote. In the so-called contagious forms, so far as known, 
the infection possesses a more marked preference for the milk 
gland as a habitat and acquires a degree of virility which 
greatly favors transmission, and the means which might occa¬ 
sionally cairy infection under ordinary conditions now becomes 
an effective and common bearer of contagion from infected to 
healthy, so that infected bedding or floor may answer, or the 
tail may transplant the infection from cow to cow, while the 
milker carries the disease from affected to healthy on his un¬ 
washed hands, or if this is not enough, uses milk from an 
infected cow to moisten the teats of a healthy one and trans¬ 
mits it in this way through the milk. In a recent outbreak of 
mastitis in ewes, investigated in our clinics, it was found that 
the lambs were puny and emaciated, and upon close examina¬ 
tion it was observed that they had a pustular eruptive affection 
of the lips and nose, caused apparently by streptococci, which 
where not distinguishable from those found in the gangrenous 
udders of the affected ewes. 
Here then we had good clinico-bacterial evidence of trans¬ 
mission from lamb to ewe, and vice vevsa , in nursing. 
If we carry our comparison further we have an exceedingly 
vascular glandular tissue enclosed within a firm sheath of yel¬ 
low elastic and fibrous tissue from the abdominal tunic, which 
once the parenchymatous tissue becomes engorged or inflamed 
the investing aponeurotic capsule prevents yielding to the 
swelling, leading to compression of the inflamed tissue with 
