I52 | BACTERTA IN MILK 
the switching of her tail, and by the rubbing of her skin by the 
milker. Since the milk-pails are frequently widely opened, they 
receive a large amount of this filth, which consists of almost every 
. 
: 
‘ 
tye, ae 
* 
a eN, 
ah rare er ae ee : 
b Lp ¢ Ne idiom, 
arte ee ete t 
: ora 
ye taht oe 
“Sane e ag 
= 
on 
=. * 
a 
cf 
2 
cee 
Eee 
oe 
tate 
aoe: 
| “Fic. 28.—A cow’s udder cut across and showing the milk ducts. 
conceivable kind of material. Besides excrement there are insect 
wings, grass, straws, hairs, and many other small particles, all 
bacteria laden. | | | a | 
