PARASITES OF ANIMALS. 189 
garded as belonging to the Acarians, with the true mites. In 
the adult state it inhabits the nostrils and frontal sinuses of 
dogs and wolves, and more rarely, of horses and sheep. The 
larva, formerly described under the name of Pentastoma den- 
ticulatum, lives in cysts on the outside, or in the outer por- 
tion, of the liver of sheep, deer, antelopes, peccary, porcu- 
pine, Guinea-pig, rabbit, hare, rat, and cat; and some- 
times invades the human body in the same way. It has also 
been found free in the visceral cavity of the body. 
In the mature state (Figure 84) the body is long, lance- 
shaped, tapering behind, flattened below, and divided into 
about ninety segments by transverse lines. The segments 
next to the head bear two pairs of small, but strong and 
Figure 84. sharp, retractile claws, which represent the true 
fon, legs of ordinary mites. The mouth is broad- 
—= oval, and provided with a hard chitinous lip. 
The segments behind the head are perforated 
by small openings, regarded by many as 
spiracles, or breathing pores. The adult is 
smooth, but the larve are covered with many 
rows of small, sharp spines. The male is 
only .07 to .08 of an inch in length, but 
the female becomes three or four inches long, 
and half an inch wide. The female genital 
opening is in the tail, that of the male, in the 
middle of the front part of the abdomen. They 
are oviparous, and the young undergo a com- 
plete and remarkable metamorphosis. 
The adults live in the nasal cavities of dogs, and 
produce an irritation of the delicate membranes, which 
causes a flow of mucus, often accompanied by sneez- 
ing. The eggs discharged with the mucus may ad- 
here to vegetables or fruit, or get into drinking- 
water, and in these ways gain admittance to the stomach of 
man, or other animals. In the stomach they hatch into mi- 
nute embryos, furnished with a boring apparatus and two pairs 
of double claws. They bore their way through the intestines 
in the liver or other parts, and soon become dor- 
and lodge in the Digitized by Mictocoft® 
