374 REPORT OF THE COMMISSIONER OF AGRICULTURE. 
spiculum measures about 1 line, and is furnished with afunnel-shaped 
membranous sheath. The female is 14 to 2 inches in length, the thick 
portion varying from 4 to 3 of aninch. The posterior portion is brown- 
ish, filled with eggs, and ends in a blunt point. The ova are 0.052 mil- 
limeters in diameter, with a transparent button-like prolongation at each — 
pole. 
Like as with other round worms, the ova are laid in the body of the 
host, but passing out are hatched in water, &c., the young spending 
their early life in pools, streams, &c., and gain access to the body in 
food and drink. The worm we are at present considering is especially 
injurious because of its infesting the human being as well as the pig. 
Living in the large intestine, it bores its head and much of its anterior 
filiform body deeply (4 inch) into the mucous membrane and sucks the 
\blood. When present in large numbers it determines active inflamma- 
tion of the large intestines, with costiveness or diarrhea, and a rapidly- 
advancing bloodlessness. Inasmuch as the seat of its ravages, the 
cecum and colon, is specially obnoxious to the lesions of the true hog- 
fever, epizootics caused by the undue prevalence of these worms are 
very liable to be confounded with the latter disease. The worms are so 
small that they are easily overlooked among the solid contents of the 
viscera, unless special care is exercised in the search. 
Sclerostomum dentatum (Diesing).—This is another small worm of the 
excum and colon of pigs, found on one occasion only in my experimental 
animals. It varies from 4 to 4 inch in length and is about + line in thick- 
ness, hence perhaps more easily overlooked than is the whip-worm, but 
no less injurious. The body is of a dark gray, brown, or black, accord- 
ing to its contents; the tegument covered with very fine transverse strie, 
head broad, mouth terminal, round, and furnished with six very sharp 
horny teeth, with which to penetrate the mucous membrane. The gul- 
let is broad and club-shaped, and furnished with two salivary glands, 
opening by delicate canals into the mouth. Intestine wide and sinuous. 
Male, $ inch long, ¢; inchin thickness; tail furnished with a bell-shaped 
membranous expansion, supported by three rays, but open on one side. 
Testicle single and extended in a sinuous manner from near the gullet 
to the tail. Two delicate spicule. Female, 4 to 5 lines in length, tail 
slowly narrowed and terminated abruptly with a sharp projecting point. 
Ovaries very tortuous, extend from near the gullet to the tail, where 
they end in a globular enlargement, beneath which, and close to the 
point of the tail, is the vulva. The ovoid eggs are laid in the intestines, 
and carried out with the dung, in which they will hatch, and give exit 
. to the embryo worms on the third day. Like all this family of round- 
mouthed worms, this fixes itself to the mucous membrane by its mouth, 
penetrates the tissues with its sharp teeth, and lives upon the blood. If 
present in large numbers it may establish such a drain that the host 
becomes pale and bloodless, rapidly loses condition, and perishes from 
anemia. It will also, like the whip-worn, irritate the bowels and bring 
on fatal inflammation, with constipation or diarrhea. In both cases 
alike the lesions are in the cecum and colon, the common seat of uleera- 
tion, &c., in the specific fever; hence the epizootic is liable to be set 
down as hog-cholera. It should be added that some members of the 
family of Sclerostomata, and notably the Sclerostomum equinum (Scleros- 
tomum of the horse), pass a portion of their early life encysted in the 
mucous membrane and even in other internal organs, and there is some 
reason to suppose that the Sclerostomum of the pig has similar habits, 
which add materially to the irritation caused by its presence in large 
numbers. The pigs in Virginiareputed as dying from hog-cholera, caused 
