BRAIN v. MUSCLE IN NATURE 175 
How is it, then, seeing the enormous advantage in the 
struggle for existence which the possessor of a large 
brain enjoys, that natural selection has not developed 
more clever animals with large brains? How is it that 
all existing species are not as cunning as the proverbial 
serpent? Why is the average animal so lacking in 
intellect ? 
It is hardly necessary for me to adduce proof of this 
deficiency of brain-power among animals. Even Mark 
Twain noticed it; that humorist does not think much 
of the wit of an ant! 
A pair of swifts once selected as the site for their nest 
the gateway of one of the colleges at Oxford. This 
was against regulations. So the college porter removed 
the nest. 
The birds immediately began to build another on the 
identical site. This was also ruthlessly destroyed. The 
birds, with greater perseverance than intelligence, tried 
to construct a third nest in the same place. This was 
not obstinacy on the part of the swifts. They were 
unable to put two and two together ; their brain-power 
was insufficient to enable them to understand that man 
objected to their nest being built on that particular 
site. 
A dog is supposed to be an intelligent animal, but it 
will run away from a stuffed bear. An elephant, who is 
the wise man among animals, will actually pick up its 
own goad and hand it to the mahout! 
But why multiply instances showing the limited 
brain-power of animals? Dozens of examples will 
occur to every one of my readers. It must not be 
