120 VETERINARY PARASITOLOGY 
These Cysticerci may be found in any organ, but 
voluntary muscles are usually affected. 
The most common site is in the muscles of mastication 
—the masseter, pterygoids, and in the tongue.. Then, in 
order, follow the heart, gluteal, intercostal, cervical, 
psoas, and pectoral muscles. 
The Cysticerct bovis are never present in such numbers 
as are the Cysticerct cellulose, and, moreover, they 
quickly become calcified. 
Symptoms.—Usually nil. 
When ingested by man, the Cysticercus develops into 
Tenia saginata in the intestine. 
TRICHINOSIS. 
This is the name applied to the condition arising from 
the presence of Trichina spiralis in the body of the pig 
or man. 
Trichina spivalis is a member of the family Tricho- 
trachelide. : 
The adult male worm is about 1 to 5 millimetres in 
length, and the female 3 to 4 millimetres. They possess 
very slender bodies, tapering at each end, with no trans- 
verse striation. The female is ovoviviparous. 
LirE-History.—The adult stage is passed in the intes- 
tine and the larval stage in the muscles. 
When flesh infested with encysted larve has been 
ingested by a suitable animal, more especially the pig, 
or even man, the cysts become partially digested and 
the larve are set free. After an interval of a few days, 
they develop into sexually mature Trichine, copulate, 
and the females soon deposit embryos. The number 
produced by a single female at one ovulation may exceed 
10,000. The embryos then proceed to migrate to the 
muscles, either by boring through the intestinal wall or 
by the aid of the blood or lymph streams. The average 
