c shock if
they touched pans of any color save the particular one. They soon
learned to avoid all the pans except those of this tint. So, by many
different methods, he trained them to recognize shades and tints until
they could discriminate between seven shades of red and as many shades
of green, and in many ways they manifested more mental ability than
any untrained dog. While these dogs were being trained, another group
of dogs were being deprived of the use of sight by being kept in a
darkened room.

At the end of the year both groups of dogs were killed and their
brains dissected. He found that the dogs kept in the darkness had
less than the usual number of cells in the seeing areas, and the cells
were smaller, while the dogs which had been trained to discriminate
between tints and shades of color many times a day had a far greater
number of larger and more complex brain-cells in the seeing areas than
any dog of that age and species ever had before. "Therefore," says
Professor Gates, "mind activity creates organic structure."

Prof. Gates discovered other things of equal importance. He carried
his observations to successive generations, and found that the fifth
generation was born with a far greater number of brain-cells than
could be found in animals not descended from trained ancestors.

This is not only interesting, but of value. You will remember, in our
talk concerning your value, we spoke of your value to the race, and
learned that in cultivating yourself in any direction you were adding
to the welfare of future generations. That was only a general
statement, and now you can see how it can be. You see that if you can
make more brains for yourself you are also making more brains for your
posterity. Or if you fail to make brains for yourself, posterity will
in like degree be defrauded.

Many people have the idea that we are obliged to be satisfied with our
dower of mental ability, and so are excusable for failing to reach as
high a level as some others. If we really believed that we could
create brains we would not sit down and sigh over small mental
capacity, but go to work at once in building minds for ourselves.

And first, we must learn to control our thoughts and make them go
where we send them. In too many cases thoughts wander here and there,
with no power governing and guiding them.

When we are sauntering in the wood we sometimes come upon pathways,
and we know at once that many, many footsteps o