[ March 
28 Psyche 
was then made and it seemed to be entirely free from the 
fleas. 
It was very easy to collect the dead and stupefied fleas 
from the bottom of the jar. Inverting the jar over a piece 
of white paper caused the greater number of them to fall 
on the paper from which they were transferred to tubes 
of alcohol. The few that remained sticking to the inside 
of the jar were easily picked up on the side of a dissecting 
needle wet with alcohol. 
A total of 148 fleas were collected from the peccary at 
this time and although the animal was kept at the labora- 
tory for several weeks and was examined at frequent in- 
tervals no more fleas were ever found on it. 
A short time later there was an occasion to examine a 
number of marmosets, or squirrel monkeys, Leontocebus 
geoffroyi (Pucheran), for possible ectoparasites before 
placing them in the animal house at this laboratory. These 
animals had been recently captured and being vicious biters 
were difficult to handle in so far as examining them closely 
for ectoparasites was concerned. Since they were hardly 
larger than a squirrel and it was necessary to hold them 
tightly in gloved hands in order to prevent biting, there 
was but little of an animal’s body left exposed for examina- 
tion. By using the chloroform- jar-method the examination 
of these monkeys was simplified to a great extent and it 
was quite surprising to find so many of them infested 
with fleas. Although the short snout of this species of 
monkey precluded using adhesive tape as a muzzle the 
towel and skin when held together at the nape of the neck 
prevented them from turning to bite or moving to any 
great extent. When this method is used on animals hav- 
ing prehensile tails, such as monkeys, opossums, etc., the 
tail is usually fastened to the hind feet in order to keep 
it away from the top of the jar. 
A black spider monkey, Ateles dariensis Goldman, that 
was found to be heavily infested with lice was treated with 
this chloroform vapor method and Pediculus to an esti- 
mated number of from 4000 to 6000 were obtained. 
Numerous opossums, Didelphis marsupialis etensis Al- 
