The Yale expositor. (Yale, St. Clair County, Mich.) 1894-current, 1913-10-23

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presence stimulates human beings TO eat clay ana
earth. But there is another route, and one OF the
rumances of science must now be explained To-
wards the end of the last century, when cholera
was prevalent in Alexandria, Doctor Looss, the
distinguished parasitologist, was working in the
local laboratory at the larva of ancyostoma. In
transferring some of the water containing larvae
from one watchglass to another by means of a
ppette he accidentally split drop on to the back
of his hand. He did not wait to wipe il off, but
after a time he noticed that the place where the
drop had fallen intensely irritable and had be-
come REDEEMED and nhamed. He then made
further experiment. placing crop of the mud
swarmng with larvae on the back of his hand he
allowed il partially to dry up. The burning and
the reddening of the skin began over again, and a
little later when he removed what was left of the
fluid very few of the larvae to be found The
great majority of them had disappeared. These
little trihes gave Doctor Looss "furiously to
think" as the French say and he then repaired
to the hospital where he found a boy whose leg
was about to be removed He dropped little of
the fluid full of ancyostoma larvae on the leg, and
after the leg cut off the area in question was
removed and cut into sections. When these Sec
tions we're examined through the microscope the
little ancylostoma larvae forcing their
way down into the body through the skin, espe-
cially travelling by the hair focles, and to
lesser extent through the sweat glands into the
deeper layers OF the skin. 1t was, of course, i'm
possible TO pursue this work with the human
ancylostoma and Doctor Looss had to carry
his work with another species. The larvae of A
caninum traced into the blood vessels and
lymphatics Of the dog Swept along in the blood
stream, they easily reach the lungs. Once arrived
i'm the lungs the larvae have no difficulty in trav-
ersing the soft pulmonary tissue and making their
way in the cavity of the respiratory organs
Thence they travel along the bronchial tubes. and
to the windpipe and into the larynx and up al
most into the mouth and here they turn back into
the oesophagus and down into the stomach and
intestine. The whole of this remarkable journey
takes from seven to ten day. They then shed the
skin of their second moult. and later, when they
reach the alimentary canal they undergo third
and fourth ecdysis or moult. In eight days they
become capable of reproduction, and in very few
more days the eggs are then passing away from
the body of the host. The whole cycle of their
lifehistory has taken, under favorable circum-
stances. from month to six weeks; under unfa-
vorable circumstances It can be almost indefinite
ly prolonged. The truth of this very remarkable
and, until Doctor Looss investigations quite I'M
heard of lifehistory is accepted Doctor Sam
bon, however, thinks that In many cases the an
cylostoma larvae reach the alimentary canal with
the blood stream and directly penetrate its walls
without passing through the lungs
Since the middle of the seventeenth century a
fatal disease has been known to exist in the
warmer parts OF America. In 1913 Piso I'm his
Historic Medico Braziliae" gives an account
OF disease which he calls "Oppilacao" aud