- A small, slender nematoid worm (Trichina spiralis) which,
in the larval state, is parasitic, often in immense numbers, in the
voluntary muscles of man, the hog, and many other animals. When
insufficiently cooked meat containing the larvae is swallowed by man,
they are liberated and rapidly become adult, pair, and the
ovoviviparous females produce in a short time large numbers of young
which find their way into the muscles, either directly, or indirectly
by means of the blood. Their presence in the muscles and the intestines
in large numbers produces trichinosis.