TRTCHINjE. 
499 
beyond all question the presence of living trichinae which were 
capable of maturing, fructifying and developing young when fed 
to other animals, for a period of eleven and one-quarter years 
from the time the invasion of the hog first took place. 
Although the encapsulated trichinae suffer no changes while 
confined in the muscles of a living organism, yet the introduction 
of portions of such muscles into the intestinal, tract of man, or 
other suitable animal, causes rapid changes in their condition. 
The processes of digestion soon set the embryonal parasites free 
from their encapsulated condition, three to four hours being 
sufficient to the purpose; the freed parasites rapidly complete 
their development, becoming matured trichinae; 30 to 40 hours 
are in general sufficient to complete this metamorphosis. In cases 
of fresh invasion, when the capsules have not become hardened 
to any great degree, 24 hours have been found sufficient to de¬ 
monstrate the presence of sexually matured trichinae in the in¬ 
testines of animals fed with such flesh by way of experiment. 
Nevertheless, one often finds parasites still enclosed in their cap¬ 
sules on the third day after feeding such flesh to an animal. 
There is scarcely another helminth by which this matured 
stage is reached in so brief a period. 
Under these circumstances, it must be evident that the changes 
necessary to maturity, by these parasites, must be of a very in¬ 
significant character. 
As a rule, sexual connection takes place within two days 
from the time the trichinae become free. 
The parasites increase in length and thickness, and in the 
female the uterus fills with fructified ova, which soon develop 
into embryos enclosed in the body of the female. 
The female intestinal, or matured parasite, lives from five to 
six weeks, and produces at least 1,500 embryos, (Leuckart.) 
The newly-born embryos are at first buried in the mucous 
which lines the intestinal tract; a microscopical examination of 
such mucous will reveal them as free and movable parasites. The 
embryos soon begin their migration and dispersion over the 
organism, the first act being the penetration of the intestinal 
parsities. It seems still to be a matter of discussion as to the 
