PARASITES OF THE ALIMENTARY TRACT 83 
PARASITES INHABITING THE ALIMENTARY 
CANAL OF THE PIG. 
In the cesophagus Ganglvonema scutatum may be 
found. 
Small Intestine. 
Echinorhyncus Gigas.—This worm belongs to the 
Acanthocephala, or thorn-headed worms. It is cylindri- 
cal in shape, and of comparatively large size. The male 
reaches Eo centimetres in length, while the female 
ranges from 30 to 40 centimetres. 
The head carries a retractile proboscis, armed with a 
large number of hooks, arranged in transverse rows. 
The body is greyish in colour and of variable diameter 
throughout its length. 
The male possesses a bell-shaped caudal pouch, while 
in the female the caudal extremity is blunt and rounded. 
The life-history has not been clearly demonstrated, 
but it appears that after the ova, which are elliptical 
in shape, have left the pig, the immature embryos are 
ingested, while contained in the larve of insects ; as in 
the May-bug, cockchafer, or even in the bodies of certain 
snails. 
The worms may be free in the intestine, but usually 
are attached by the head, which is buried in the mucous 
membranes. Sometimes the worm bores deeply into 
the mucous membrane, and on being removed leaves a 
scar. Perforation, with subsequent traumatic peri- 
tonitis, is not rare. 
These worms are not common in the United Kingdom, 
but are of very frequent occurrence in France, Germany, 
and the United States. 
Symptoms.—These vary according to the number of 
