THE COMMUNICABLE DISEASES 521 
with a collar and chain by which they are pulled into the 
corner of the cage and held, while the door is opened to 
permit a helper to catch the feet and arms. Two experi- 
enced men can take the temperature of any monkey that 
can be handled at all safely. The knowledge of how 
to do such work reduces the excitement of the animal 
and renders more accurate the observation of its tempera- 
ture. During the period of temperature-taking food is 
given in small quantities and only after the record is 
made. 
Temperatures are taken in all animals by rectum, (3) 
the thermometer, a separate instrument but always the 
same for each animal, well greased with plain vaseline, 
being passed along the anterior rectal wall and allowed 
to register for twice its indicated speed. During the pre- 
liminary work, special instruments of officially standard- 
ized accuracy were obtained by Doctor Brown but once 
the normals were obtained, ordinary good thermometers 
registering from 94° F. to 108° F. have been employed. 
If the record vary very much from the expected, such 
as the figures obtained at the same time on the preceding 
day, or if the rectum be crowded with feces, the instru- 
ment is shaken down and reintroduced. In order to 
facilitate timing of exposures we use sand glasses of 
three minute run. 
After some experimentation by taking records at vari- 
ous times of day it was found that monkeys as a group 
do not have a uniform temperature during twenty-four 
hours but register a higher figure during daylight than 
during darkness. This is probably due, as I shall dis- 
cuss, to the period of activity, not to the time of day. 
Figures obtained at various hours indicated that the 
highest and lowest temperature would be obtained if 
records were made at four-hour intervals at three, seven 
and eleven o 'clock AM. and PM. To give the normal tem- 
(3) The temperature in the axilla is often .5° F. higher than by 
rectum, but the difficultie8 of the axillary method render it Impracticable. 
34 
