PARASITOLOGY. 117 
Haemoncuus Contortus (Contortus—twisted), 
b Synonym.—Strongylus Contortus. 
LJ y) Distribution.—Common in many states, 
' especially in the South and middle West. 
a. ae ae : : 
aeons Description.—Hair-like in appearance; 
Stroncyius body white or pinkish white in color; 
ooo the mouth is nude; two lateral papillae 
b, Female, are noted a short distance from the head; 
the cuticular surface has fine transverse 
striations ; the caudal pouch is bilobate, 7. ¢., the 
pouch is divided into two parts; the body of the 
female terminates in a pointed tail; the male meas- 
ures four-fifths of an inch in length, the female about 
one inch. 
Lite Cycle.—The female is oviparous. The ova 
are passed from the animal in the feces; the egg 
thus passed has been found to be undergoing seg- 
mentation, and has hatched in from two to three 
days. The embryo is very small and is provided 
with a fine-pointed tail. Inthe development from 
the embryonic to the fully developed larval stage, it 
moults at least twice; the embryo becomes shriv- 
eled in the last moult, and remains in the skin, in 
which state it is usually found upon blades of grass 
or other objects. In this state it can retain its vital- 
ity for several weeks, withstanding desiccation and 
freezing. When taken into the stomach the larva 
becomes revivified and developes into the adult 
stage, The worm is a bloodsucker and is often 
found attached to the mucous membrane, holding on 
by means of its buccal armature. 
Animals Intested.—The ox, the sheep and the goat. 
Parts Intested.—Abomasum and intestines. 
