Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-01-20
ANIMAL PARASITES.
A RECENT DISCOVERY GIVES SCIENCE
ANOTHER START

The Department of Agriculture Trying to
Find Means to Fight Them-It Has
Made Great Discovery-A Work of In
terest to AL
WASHINGTON. Jan. ia recent dis.
covery to the effect that the trichin9 OF
pork, which caused the American hog to
be shut out Of Europe so long. are from rats
has given new impetus to the pursuit of a
line of investigation which has been claim
ing the attention of the United States Gov
ment. DIR. Leuckhart, the great Leipsic
professor, who made the discovery, ascer-
tanned by the dissection of rats that 40 per
cent of them were infected by trichina.
Rats are cannibals They eat their own off
spring and each other, and spread the in
fection. Whether they ever die of trichino-
sis is not known, although it makes them
lame sometimes. Pigs devour them and
contract the complaint. Human beings in
their turn eat the pigs, and the trichina
develop, with fatal results frequently
The Department of Agriculture is at pres
ent giving earnest attention to the study of
animal parasites, with view of finding out
methods for fighting against some of them
which cause loss of many millions of dol
lars yearly to farmers. 1t has made big
discovery recently in relation to the fatal
disease of cattle called Texas fever, which
is caused by a minute animal called proto-
zoon, that feeds on the red corpuscles in the
blood and destroys them. Recent develop
ments of knowledge reveal the protozoa as
producers of morbid complaints. It has
been ascertained that the cause of malaria
is protozoon which feeds on the blood cor
puscles, and another microscopic foe of like
i y r..
of dysentery. Undoubtedly many disorders
not now understood will eventually be re-
ferred to a similar origin.
The department is trying to discover
means for combating another parasite,
which causes loss of nearly s., 800, 900 q
year in cattle slaughtered in Chicago. It is
the dreaded hee! hy, which lays its eggs on
the backs of the animals, the worms Matched
from them boring through the skin and re-
naming buried for several months in the
flesh. On emerging they fall to the ground
and form the chrysalis condition, come out
as perfect flies, ready to lay their eggs on
the backs of other cattle, that being their
only method of reproduction.
Another insect, known in the West as the
gadf1y, attacks horses, laying its eggs on
the animals. The horse licks itself and
conveys the eggs to its stomach, where they
are Matched, the worms clinging to the
stomach walls. Very often they bore
through the stomach and kill the horse. A
parasitic worm known as the liver fluke at
taches itself during a certain stage of its
being to the liver and lungs of cattle.
During its early growth it goes through
series of astonishing metamorphoses, devel-
oping new self inside of its old self in
different shape several times. Finally it
leaves the body of the beast, and what be-
comes of it is not known precisely; but
there is no doubt that it is transformed into
a species of snail that lives in wet places
1t certainly must lay its eggs in such spots,
where the cattle lick them up, thus COM
pleting the cycle of its being
Only beginning has been made BY the
Government in the work of fighting the
parasites of animals. BY always condemn
ing the pigs which are infected with
trichina the disease will be rendered less
common. Heel flies and gadflies are COM
batted successfully and destroyed by spread
ing tar ointment over the bodies of the
beasts attacked. In its labors the Bureau
of Animal Industry of the Department of
Agriculture devotes its attention first to
studying the life history of each parasite, in
order to find out at what stage of Its exist
ence the enemy can be attacked to the best
advantage. Having procured full knowl-
edge of the habits and manner of existence
of the adversary, it is comparatively easy to
interfere with its operations.