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From the foregoing it will be seen that the entire question under 
discussion is one of simple, elementary cleanliness, honesty, and pro- 
priety ; that when due regard is had for these three factors the danger 
of infection by animal parasites, through the milk supply, is elim- 
inated ; but that such danger increases in proportion as these factors 
are ignored. 
There is no eviden.ce on record that any one of the foregoing possi- 
bilities has ever played an important role in producing any large 
number of cases of infection. Still it may be well worth while to 
refer to these possibilities briefly as contributing arguments in favor 
of a clean milk supply. 
(a and b) Water-born parasites . — If contaminated water is used 
in washing milk cans or in fraudulently diluting milk it stands to 
reason that the contamination in question may be transmitted to the 
milk and through the latter it may be transmitted to the consumer. 
In this manner any obligatory or faculative water-bom zoo-parasitic 
infection (such as amebic dysentery, coccidiosis, possibly some forms 
of distomatosis, cysticercosis, hydatid diseases, eel worms, etc.), might 
be transmitted through the milk. The dangers involved are not suf- 
ficient to cause any sensation or alarm, but they are sufficiently real 
to present contributing arguments in favor of protecting milk from 
foul and contaminated water. 
(c) Improper disposal of fecal material . — When fecal material is 
not properly disposed of, the danger is present that the infection 
which it contains may be spread in various ways, as by flies, to the 
food, and thus it may gain access to man. The danger involved in 
reference to the animal parasites is not, in general, so great as it is 
in reference to the bacterial infections — such as typhoid, cholera, etc. ; 
for in case of the zooparasites the transmission in most of the in- 
stances in which it is theoretically possible could take place only when 
the organisms had reached a certain stage in their life cycle. For 
instance, a typhoid or a cholera stool would, a priori, be more danger- 
ous when fresh than when one to several weeks old, and its danger 
would decrease with age ; from a case of amebic dysentery, hook-worm 
disease, or eel- worm infection, danger from a perfectly fresh stool 
would in general be nil ; gradually the stool would become infectious 
corresponding to the rapidity of the development of the infecting 
stage of the parasites in question; this infectiousness would increase 
to a maximum, according to conditions of heat and moisture, and 
then the infectivity would gradually decrease. If stools in an infect- 
ive condition are visited by flies or are washed into a water supply or 
are scattered in dust form, they can, according to the various con- 
ditions, form the basis of various zoo-parasitic infections, and should 
particles of such stools be accidentally carried to milk, the milk could 
