Possibly the weight of the brain
has increased during this period because of its development, and
undoubtedly its power is much greater in modern man than in this
ancient type. Prior to that there are some evidences of extinct
species, such as Pithecanthropus Erectus, the Grimaldi man, the
Heidelberg man, and the Neanderthal. Judging from the skeletal remains
that have been found of these races, there has been a general progress
of cranial capacity. It is not necessary here to attempt to determine
whether this has occurred from hereditary combinations or through
changing environment. Undoubtedly both of these factors have been
potential in increasing the brain power of man, and if we were to go
farther back by way of analogy, at least, and consider the Anthropoid
ape, the animal most resembling man, we find a vast contrast in his
cranial capacity as compared with the lowest of the prehistoric types,
or, indeed, of the lowest types of the uncultured living races.

Starting with the Anthropoid ape, who has a register of about 350 c.c.,
the Pithecanthropus about 900 c.c., and Neanderthal types registering
as high as 1,620 c.c. of brain capacity, the best measures of the
highest types of modern man show the brain capacity of 1,650 c.c.
Specimens of the Cro-Magnon skulls show a brain capacity equal to that
of modern man. There is a great variation in the brain capacity of the
Neanderthal race as exhibited in specimens found in different centres
of culture, ranging all the way from 1,296 c.c. to 1,620 c.c. Size is
only one of several traits that determine brain power. Among others
are the weight, convolutions, texture, and education. A small, compact
brain may have more power than a larger brain relatively lighter. Also
much depends upon the centres of development. The development of the
frontal area, shown by the full forehead in connection with the
distance above the ear (auditory meatus), in contrast with the
development of the anterior lobes is indicative of power.

It is interesting to note also that the progress of man as shown in the
remnants of arts and industry corresponds in {30} development to the
development of brain capacity, showing that the physical power of man
kept pace with the mental development as exhibited in his mental power
displayed in the arts and industries. The discoveries in recent times
of the skeletons of prehistoric man in Europe, Africa, and America, and
the increased collection of