the continental glaciers remain the tendency
is to destroy the river valleys. The result is to plane down the land
and, to a certain extent, to destroy all preexisting river valleys."

If this subject is studied while snow is on the ground it will be
interesting to the children to experiment out of doors in making
glaciers. If there are no hills present the children can readily make
small hills on their playground and the falling and partial melting of
the snow will do the rest.

_Lesson XXXII._ Neighboring clans are accustomed to meet at the rapids
of a river during the salmon season. At such places, and in all places
where abundant sources of food are to be found, neighboring clans
participate in feasting, dancing, and general merrymaking. Just as
scarcity of food tends to separate people, so abundance of food tends
to draw them together. At such gatherings people of different clans
exchange ideas, learn new ways of doing things and become accustomed
to act in larger groups for the accomplishment of a common purpose.

_Lesson XXXIII._ On the side of invention the throwing-stick is
a point to be emphasized in this lesson. On the side of social
cooperation, the organization of the brotherhood is the point of
interest. Such organizations are characteristic of primitive peoples,
and similar organizations among children are of common occurrence.

_Lesson XXXIV._ This lesson serves to bring out the contrast between
Fleetfoot, the brave, active young man, who is beginning to develop
the arts which require great personal bravery and force, and Flaker,
the crippled young man, whose ability is directed toward the
development of tools and the arts which later make him a priest and
medicine man. Originally, there was no sharp distinction between the
priest and the medicine man. One person performed both functions, and
in many cases this person was a woman. Later, those who made use of
supplication and entreaty constituted the priesthood, while those who
attempted to frighten the gods were known as medicine men.

_Lesson XXXV._ Overhanging rocks were made use of for natural shelters
from the earliest times. The improvement of the natural shelter by the
addition of front and side walls was a later step and was doubtless an
invention of woman. The motives for such an invention may be found in
the fact that in many places near good hunting grounds there were not
enough caves to shelter the people. Under such circumstances, as wel