PARASITES OF ANIMALS. 125 
size. It is probable that such eggs, containing embryos, 
when swallowed in the water that we drink, will be hatched 
in our stomachs by the action of the gastric juice, and that 
the young worms thus reach their destined abode. It is 
possible, however, that under the proper circumstances the 
eggs will hatch in the water, and that the free swimming em- 
bryos may be swallowed in the same way. This part of their 
history still remains uncertain. 
Symptoms. 
The presence of one or two of these parasites in the human 
intestine does not ordinarily cause any marked effects or 
noticeable symptoms. But when they occur in persons of 
delicate health, and when in great numbers, as sometimes 
happens, they may cause great disturbance of the natural 
functions of the digestive system, and induce various serious 
consequences. Cases have occurred in which from 100 to 
500 of these worms have passed from one child. They live 
chiefly in the small intestine, but sometimes enter the stomach 
and may even be expelled by vomiting. In some instances 
they have been known to perforate the walls of the intestine 
and enter the abdominal cavity, and thus even to get into the 
other organs, including the lungs, pleura, gall-bladder, etc. 
In such cases death often results. 
Their presence in the stomach and intestine causes colic 
and shooting pains, often accompanied by nausea, vomiting, 
dyspepsia, itching of the nose, and diarrhea. Owing to the 
irritation of the nervous system they may cause restlessness, 
convulsive twitchings, especially during sleep, and various 
mental disturbances. In some cases, serious convulsions, 
epilepsy, and insanity have been caused by them, and have 
been cured at once by expulsion of the worms. 
Remedies. 
The most reliable remedy appears to be santonine, but this 
is a powerful preparation, and must be used with caution. 
For children the dose is one to three grains, in the form of 
powder, which does best if taken in castor-oil or honey, 
though it may be sprinkled, over. a, piece of bread and butter. 
