TRICHINA. 
899 
dog, fox, cat, raccoon, bear, mole, hedgehog, etc. Birds are 
also very susceptible to trichina. As has been previously stated 
the adult trichina is found principally in the small intestines of 
mammals and birds. To begin with, all mammals and birds 
which are found to be infested with trichina, must have first 
eaten the infested flesh. Trichinae are found in the large and 
small intestines, but they are found more frequently in the 
small intestines. Those mammals in which trichinae are most 
commonly found are, man, pig, etc., and in the intestines of 
birds. The bird is not a favorable subject for the development 
of trichinae in the encysted state, because the cyst may pass 
through the digestive canal, and never undergo any change. 
The larva which are deposited by the worm is never developed 
in the digestive canal, but more usually in the intestines. 
When one of the mammals eat a piece of infested flesh, the 
muscular trichinae are encysted, the gastric juice dissolves the 
cyst, and the worms are set free. The fourth day after the 
worms have been set free, larvae will have undergone a syste¬ 
matic change into the adult forms. 
In testing for the adult a microscope having a magnifying 
power of 75 to 150 diameters is used; the intestines being ex¬ 
amined under this microscope. It is not until the seventh or 
eighth day that the intestinal trichinosis is noticed. The fe¬ 
males lives are of a longer duration than the males. It has 
been proven that one individual may produce from 10,000 to 
15,000 embryos. The embryos that are deposited in the intes¬ 
tines are not developed until they have worked their way into 
the striped muscles and connective tissue of the body. The 
trichina that is found in the lymphatic glands is believed to 
have been brought there by the lymphatic vessels. Neverthe¬ 
less, there are several different ways by which the trichinae may 
be distributed through the body. There are parasitic nema¬ 
todes of certain vertebrates which have been very often mis¬ 
taken for trichinae. The larval trichina has been found by ex¬ 
perts to exist in the fat as well as in the muscles of animals. 
When the sixth day has been reached the larval trichinae will 
