; 
_ 
2 Dr. G. D. H. Carpenter’s Haperiments on 
have been entirely omitted—two designed to show at a 
glance how colour and edibility are correlated, and one 
giving a comparison between the two monkeys. But the 
complete original manuscript, together with the specimens 
used, may be seen in the Hope Department, Oxford 
University Museum. 
July, 1920. 
Preliminary. 
Tue following experiments, whose object is to test the 
edibility of procryptic * insects and the relative inedibility 
of aposematic insects, a young monkey being used as 
judge, were performed while I was on active service in 
ex-G.H.A. in medical charge of two small posts near Tabora 
between Dec. 28, 1916 and Feb. 6, 1917. There was very 
little work to do, and I was often hard put to it to occupy 
myself until I discovered that there was a young monkey 
in the camp. This was a splendid opportunity, and I at 
once borrowed him and set to work. The monkey was a 
delightful youngster of the abundant grey species of 
Cercopithecus, with a whitish band. over the eyes; he had 
been obtained when very young, and consequently was 
perfectly tame and used to being handled, indeed, so 
accustomed was he to human society, that he was unhappy 
when alone. For the purposes of the experiments it was 
necessary to keep him tied up, but previously he had been 
allowed to run where he pleased. 
The Margin of Error. 
Experiments upon the edibility of insects to a monkey 
need to be very carefully and systematically conducted, 
with full recognition of the very wide margin for error. 
It is quite useless to offer an insect to an unknown captive 
monkey in an unknown state of hunger or repletion, and to 
draw conclusions from that. In the first place, a knowledge 
of the monkey’s individual temperament and habits 1s 
essential, in order that one may interpret correctly its 
behaviour when an insect is offered. The monkey must be 
so accustomed to the observer that his presence has no 
disturbing effect; but, on the other hand, one has to 
* The terms Procryptic and Aposematic, first used by Prof. 
E. B. Poulton, F.R.S., in his book, ‘* The Colours of Animals,’’ 
Lond., 1890, imply respectively a protective resemblance to sur- 
roundings, and conspicuous ‘* warning ’’ colours, 
