ty, and his membership in society is dependent
upon his membership in a social group.

Without making too much of the comparison between a living organism,
like the human body, and a society, the similarities between the two are
striking. The human body consists of various systems, such as the
circulatory system, the nervous system, the digestive system. Each of
these systems is composed of many parts, having separate functions to
perform. The circulatory system, for example, consists of the heart,
veins, arteries, capillaries, the blood, etc. These various parts of
each system are in their turn made up of different kinds of tissue. The
heart is a complicated organ consisting of muscle tissue, nerve fibers,
blood vessels, etc. Muscles, nerves and blood vessels are in their turn
composed of living cells, each of which contains the mechanism of a life
cycle. Among the unit cells, the various tissues, organs and systems of
the body, there is a working harmony. The whole complex machine
functions in unison. If one of the organs fails to do its work,--if the
heart fails to pump blood or if the lungs fail to inhale oxygen,--the
whole body ceases to function or "dies."

Throughout the series, from the single cell to the entire organism, the
human body is built up compositely. This method of composite structure
holds equally true in the composition of modern society.

A modern society or community consists of various systems, such as the
educational system, the economic system, the political system. Each of
these systems is, in its turn, composed of institutions. Thus, for
example, the educational system consists of the common schools, the high
schools, the normal and professional schools and universities, the
special schools, and so on. Each city school system is a going concern
with its pupils, teachers, officials, school buildings, textbooks,
courses of study. Each school building, each class room, each group of
pupils, is a social unit, composed either of individuals or of groups.
Like the single cell of the human body, the individual pupil is a living
organism, and it is out of a multitude of such organisms variously
grouped that school systems are built.

The social machinery, like the machinery of the body, must work
smoothly, otherwise misery will be the inevitable result. If the
educational or the economic life of a community breaks down, the whole
community suffers, as does the body through the failure of an import