of skulls forty-five per cent, of
the Australian had a cranial capacity of 1,200 to 1,300 c.c., while
46.7 per cent. of modern Parisian skulls showed a capacity of
between 1,500 and 1,600 c.c. The skull of the gorilla contains about
five hundred and seventy cubic centimetres. Broca found that the
cranial capacity of 115 Parisian skulls, of probably the higher
classes from the twelfth century, averaged about 1,426 cubic
centimetres, while ninety of those of the poorer classes of the
nineteenth century averaged about 1,484. His observations seemed to
prove that there has been a steady increase in Parisian cranial
capacity from the twelfth to the nineteenth century.

Turning to the actual weight of the brain, that of Cuvier weighed
64.5 ounces, and a few cases of weights exceeding 65 ounces have
been recorded. The lowest limit of weight in a normal human brain
has not yet been accurately determined. From 34 to 31 ounces have
been assigned by different writers. The brain of a Bush woman was
computed by Marshall at 31.5 ounces, and weights of even 31 ounces
have been recorded without any note to show that the possessors were
especially lacking in intelligence. As Professor Huxley says in his
"Man's Place in Nature," a little book which I cannot too highly
recommend to you all, "It may be doubted whether a healthy human
adult brain ever weighed less than 31 or 32 ounces, or that the
heaviest gorilla brain has ever exceeded 20 ounces. The difference
in weight of brain between the highest and the lowest men is far
greater, both relatively and absolutely, than that between the
lowest man and the highest ape. The latter, as has been seen, is
represented by 12 ounces of cerebral substance absolutely, or by
32:20 relatively. But as the largest recorded human brain weighed
between 65 and 66 ounces, the former difference is represented by 33
ounces absolutely, or by 65:32 relatively."

But there is another characteristic of the brain which seems to bear
a close relation to the degree of intelligence. The surface of the
human brain is not smooth but covered with convolutions, with
alternating grooves or sulci, which vastly increase its surface and
thus make room for more gray matter. Says Gratiolett: "On comparing
a series of human and simian brains we are immediately struck with
the analogy exhibited in the cerebral forms in all these creatures.
There is a cerebral form peculiar to man and the apes; and so in the
cerebral convolut