THE INTELLIGENCE OF MAMMALS 233 
The labyrinth and puzzle box devices of our psychological 
laboratories have the advantage of enabling us to study 
animal behavior under strictly controlled conditions, and 
they readily yield results in a form capable of easy tabula- 
tion, but they have been criticized with a certain measure 
of justice on the ground that the artificial conditions to 
which the animals are exposed make them appear more 
stupid than they really are. A fox in its wary prowlings 
for prey or in its attempts to outwit its pursuers may mani- 
fest a considerably higher degree of intelligence than it 
would show if confined to a box from which it had to liber- 
ate itself by raising levers and pulling bolts. In wild an- 
imals especially there is a falling off of spirit and initiative 
when they are placed in an artificial environment. The 
lion of the desert is a very different creature from the lion 
of the circus; the keenness and alertness with which the one 
conducts his hunt for prey, stand in marked contrast with 
the melancholy and reluctant performances of the other 
when under the trainer’s whip. Other animals such as 
raccoons and some monkeys take to a life of confinement 
much more readily, and therefore afford particularly valu- 
able subjects for experiment. Those experiments are of 
the most value which stimulate to the greatest extent the 
free exercise of an animal’s faculties, and in order to secure 
_this result an animal’s instinctive interests and promptings 
should be given, so far as possible, free play. 
The experiments of the last few years have given us a 
more just estimate of the nature and limitations of the 
intelligence of the higher animals than we formerly possessed. 
Animal psychologists have come to scrutinize their results 
much more closely and to be much more cautious in their 
statements regarding what goes on in the mind of the animal 
studied. The interpretation of what mental processes are 
