225 
act as a mechanical bearer of the germs. In general, however, the 
chances of such method of infection seem rather remote, in so far as 
the animal parasites are concerned. 
( d ) Personal habits of persons who handle milk. — It seems possi- 
ble that the personal habits of persons (such as milkers, servants, 
etc.), who come into more or less close contact with milk, might be a 
more appreciable element than any of the foregoing in infecting the 
milk, although even in such cases the infection in question, namely, 
by animal parasites, would be of far less importance than a typhoid 
infection. For instance, while a milker who is a typhoid “bacillus 
carrier ” would be an element of grave danger to the public health, 
an infection (in that person) of pinworm, of pork tapeworm, and 
perhaps of Cochin China diarrhea, might be of some slight impor- 
tance, in reference to the possibility of their transmission through the 
milk supply; but if that person had coccidiosis, the fat, or the broad 
tapeworm, or flukes, ellworms, or whipworms, such infections would 
be without significance, so far as the public milk supply is concerned. 
(e) Fecal material from animals. — It is not a pleasant thought 
that our milk supply may contain fecal material from various ani- 
mals, but such is unfortunately the case. Upon several occasions 
other divisions in this laboratory have submitted to the Zoological 
division for determination, sediment taken from bottled milk and 
such sediment has proved to be feces from rodents — either rats or 
mice. Now it is supposed that at least 3 intestinal parasites from 
the rats and mice are capable of developing directly in man. In the 
case of one of these parasites (dwarf tapeworms) , the usually accepted 
view is open to question, since the form in man is perhaps specifically 
distinct from the form in rodents ; in the' case of a second parasite 
(the trichina worm), the transmission from rat’s feces to man is 
probably possible, but more theoretical than practical: in the case of 
a certain protozoan infection ( Lamblia ) it is quite possible that a 
real, though perhaps not very frequent danger is present of its trans- 
mission through the milk supply. 
(/) Infections from dogs and cats.— Probably the greatest danger 
of the transmission of parasites from dogs and cats through the milk 
supply lies in the accidental infection with hydatids, from contamina- 
tion with canine feces, and the accidental presence, in milk, of the cat 
and dog flea, in which a larval tapeworm occurs which is transmissible 
to man. In neither case, however, is any instance of these parasites 
positively traced, so far as I know, to this method of infection, 
although such method must be admitted as theoretically possible. 
24907— Bull. 41—08 15 
