THE EVOLUTION OF THE MIND. 267 
To each of these monkeys I gave an egg, the first 
that any of them had ever seen. 
The baby monkey, Mono, being of an. egg-eating 
race, devoured his egg by the operation of instinct or 
inherited habit. On being given the egg for the first 
time, he cracked it against his upper teeth, making a 
hole in it, and sucked out all the substance. Then hold- 
ing the egg-shell up to the light and seeing that there 
was no longer anything in it, he threw it away. All this 
he did mechanically, automatically, and it was just as 
well done with the first egg he ever saw as with any 
other he ate. All eggs since offered him he has treated 
in the same way. 
The monkey Bob took the egg for some kind of 
nut. He broke it against his upper teeth and tried to 
pull off.the shell, when the inside ran out and fell on 
the ground. He looked at it for a moment in bewilder- 
ment, took both hands and scooped up the yolk and the 
sand with which it was mixed and swallowed the whole. 
Then he stuffed the shell itself into his mouth. This act 
was not instinctive. It was the work of pure reason. 
Evidently his race was not familiar with the use of eggs 
and had acquired no instincts regarding them. He 
would do it better next time. Reason is an inefficient 
agent at first, a weak tool; but when it is trained it be- 
comes an agent more valuable and more powerful than 
any instinct. 
The monkey Jocko tried to eat the egg offered him 
in much the same way that Bob did, but, not liking the 
taste, he threw it away. 
The low intelligence of the lower animals—as the 
fishes—may be at times worse than noneat all. If mental 
development were a real advantage to fishes it would 
arise through natural selection. The fishes taken in 
a large pound net, as I have observed them in Lake 
