THE ANIMAL PARASITES 657 
Turning now to the active curative side of the sub- 
ject, what medical means we have against parasites ap- 
pertain for the most part to the intestinal ones. The 
treatment of tapeworms is very hazy and unsatisfactory 
— areca nut is perhaps more useful in animals than any 
one other drug. For round worms santonin is most to 
be depended on although turpentine is useful against the 
round worm of the Equidae. The dosage of santonin per 
month has been — for large bears, ten grains; for lions, 
tigers, large pumas, six grains; for jaguars, leopards, 
hyenas, four grains ; for wild cats, etc., two grains. The 
dose of areca nut recommended for Carnivora is two 
grains per pound of body weight. Since ungulates do not 
stand areca nut well, iron sulphate may be used. For 
animals the size of a horse the dosage is two drams, and 
to this one or two grains of arsenic trioxide may be added. 
On the basis of very carefully controlled experiments on 
dogs. Hall recommends carbon tetrachloride for hook- 
worms in these animals — 0.3 mils per kilo of body weight, 
without purging. Its efficacy has been confirmed lately 
but we have not had the occasion to test it. 
From time to time we have broached other lines of 
medication against worms which may be worth while re- 
lating if for nothing more than to illustrate the uncertain 
ways of our vermifuges when applied to wild animals. 
I can speak first of thymol as employed on parrots 
parasitized by Spiroptera incerta. The first thing that 
impressed us was the large dosage which birds could en- 
dure. The lethal dose for pigeons was four grains, sus- 
pended in mucilage of acacia. After we had established 
that certain parrots withstood fourteen grains in muci- 
lage, we administered on one occasion twelve grains and 
on another sixteen grains, suspended in glycerin. The 
drug is reputed to be absorbed when exhibited in the 
latter vehicle and we hoped to get a certain anthelmintic 
effect on the parasites from the blood side as well as 
from the lumen of the gut. The bird itself, a very heavily 
