68 THE AMERICAN MONTHLY [April, 
and examined them attentively ; but, not being sufficiently acquainted with 
helminthology to understand their true nature, he referred them to Professor 
Richard Owen, the celebrated naturalist of the British Museum. Professor 
Owen recognized them as new nematode worms, and gave them the name. 
Trichina, from their hair-like form; he added the specific name spzralzs 
on account of the manner in which they were rolled up in their cyst, and 
Trichina spiralis stands as the scientific name of this animal. 
The trichine, which are now known in the minutest details of their organ- 
ization and manner of life, have a distinct mouth and a complete digestive 
tube with an orifice at each end of the body. Besides this nutritive appara- 
tus, trichine, like nematodes in general, have the sexes separate, so that 
there are males and females, whjch can be easily distinguished from each 
other by the size and form of the body. 
Trichine are found in the flesh of almost all the mammals. If we eat this 
trichinous flesh, the worms are set free in the stomach as digestion goes on, 
and develop with extreme rapidity. Each female lays a prodigious number 
of eggs; from each of these comes a microscopic worm, which bores through 
the walls of the stomach or the intestines, and thousands of trichine lodge 
themselves in the flesh, where they hide till they are again introduced into 
another stomach. When the number is great, their presence may cause dis- 
orders, or even death. 
Leuckart’s experiments on animals aroused the attention of physicians, and 
then it was found that patients who had shown exceptional symptoms had 
fallen victims to the invasion of these parasites. Leuckart estimated 700,000 
trichine in a pound of human flesh, and Zeuker speaks of even five millions 
found in a similar quantity of human flesh. 
The Zrichina spiralis produces about a hundred young worms at the end 
of a week (viviparous); and a pig which had swallowed a pound of Sesh 
(5,000,000 trichinz) might contain, after some days, 250 millions, reckoning 
that only half the worms hatched were females, which is not the case, for 
the females outnumber males. It appears that trichine can become sexually 
mature in all warm-blooded animals; but the number in which they can be- 
come encysted is not so great. It appears that they are not encysted in birds. 
In the month of December, 1863, R. Leuckart wrote from Giessen :—‘ The 
trichine are playing a great part at present in Germany (with the exception 
of Schleswig-Holstein). Two epidemics have made their appearance within 
a few months, and have produced a veritable panic, so that no person will any 
longer eat pork. The authorities everywhere are obliged to subject the flesh 
of these animals to microscopic examination.’ 
We owe to Leuckart (1856 and 1857) and to Virchow (1858) our knowl- 
edge of the principal facts of the history of these worms. Virchow ascer- 
tained by experiment that they become sexually mature in the alimentary 
canal at the end of three days; and these two naturalists discovered, after 
many researches, that trichine are neither Strongylus nor Trichocephalus, 
but a different kind of nematode, which is hatched in the stomach of those 
whom it infests, and that their embry os, instead of migrating, establish them- 
selves in the host himself. The embryos of parasites “do nae usually remain 
in the animal which gives them lodging; they are evacuated, as well as the 
eggs, and are conveyed to another animale The trichine, howe are de- 
veloped to sexual maturity in the same animal in which they have been en- 
gendered. 
Eggs of parasitic worms are not usually developed in the body of the host 
of their parent, but are evacuated with the feces. The trichine are an ex- 
ception. These agamous worms, when introduced into the stomach, rapidly 
pass through their embryonic history, mature, and lay eggs. Tae young 
sarees eae 
oe 
