i88i.] 
Trichina and their Distribution . 
6 67 
add, are domestic poultry, as well as slugs and snails. 
When any animal has recently been feeding on trichinised 
matter its excrements will contain young Trichina , and 
even mature females who have not yet brought forth their 
progeny. In this manner, among dung-eating species, one 
individual may affeCt the herd. Even animals not inten- 
tionally and consciously devourers of excrement may con- 
tract trichinosis if the faeces of rats or mice are mingled 
with their food or drink. Mr. Phin suggests that the 
hippopotamus which died some time ago at the Zoological 
Gardens may have become infested with Trichina. 
A third manner in which these intruders may be spread 
from animal to animal, if less frequent in its occurrence, is 
more insidious, and may reach creatures which eschew 
impure food. Let us take the very possible case that a 
trichinised dog, cat, or rat, is drowned in a pond or river, or 
that its carcase is thrown into the water in that nasty spirit 
which dooms our streams to be the common repositories for 
filth. The body putrefies, and the Trichina present in its 
intestines, or encysted in its flesh, are set at liberty. Will 
they not be destroyed by the process of putrefaction ? No ; 
unfortunately, like most nuisances, vegetable or animal 
(human included), they are very tenacious of life. They 
have been experimentally kept for months in putrefying 
animal matter without apparent injury. If, therefore, a 
cow or a horse happens to drink the water near the place, 
it may receive into its stomach a number of Trichina. 
Now to prevent dogs, cats, and rats from being occasionally 
drowned in our rivers is a consummation devoutly to be 
wished for, but we fear beyond the power of the most 
stringent legislation. 
So far as we have gone the vegetarians may tell us that if 
we suffer from trichinosis we are justly punished for eating 
“ impure ” food. But their turn is now to come. Even 
vegetables may be contaminated. If plants are manured 
with the offal or the excrements of trichinised animals, they 
may communicate the infection. For man the chief danger 
is in case of lettuce, celery, radishes, and herbs eaten raw. 
Bearing in mind the faCts that Trichina are not in any 
moderate lapse of time destroyed by contact with putrefying 
animal matter, fseces, &c., and that they can bear prolonged 
immersion in water without injury, we may well assume 
that they will occasionally be present in sewage. Pigsties, 
slaughter-houses, &c., will occasionally be washed down into 
the sewers ; they may happen to contain Trichina. Let us 
now suppose that such sewage is used for irrigation, and is 
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