nd games of simple chase (tag games)
decline in interest. Races and other competitive forms of running
become more strenuous, indicating a laudable instinct to increase
thereby the muscular power of the heart, at a time when its growth is
much greater proportionately than that of the arteries, and the blood
pressure is consequently greater. A very marked feature from now on is
the closer organization of groups into what is called team play. Team
play bears to the simpler group play which precedes it an analogous
relation in some respects to that between modern and primitive
warfare. In primitive warfare the action of the participants was
homogeneous; that is, each combatant performed the same kind of
service as did every other combatant and largely on individual
initiative. The "clash of battle and the clang of arms" meant an
individual contest for every man engaged. In contrast to this there
is, in modern warfare, a distribution of functions, some combatants
performing one kind of duty and others another, all working together
to the common end. In the higher team organizations of Basket Ball,
Baseball, Football, there is such a distribution of functions, some
players being forwards, some throwers, some guards, etc., though these
parts are often taken in rotation by the different players. The
strongest characteristic of team play is the cooeperation whereby, for
instance, a ball is passed to the best thrower, or the player having
the most advantageous position for making a goal. A player who would
gain glory for himself by making a sensational play at the risk of
losing for his team does not possess the team spirit. The traits of
character required and cultivated by good team work are invaluable in
business and social life. They are among the best possible traits of
character. This class of games makes maximal demands upon perceptive
powers and ability to react quickly and accurately upon rapidly
shifting conditions, requiring quick reasoning and judgment.
Organization play of this sort begins to acquire a decided interest at
about eleven or twelve years of age, reaches a strong development in
the high schools, and continues through college and adult life.

[Sidenote: Relation between development and play]

Such are the main characteristics of the games which interest a child
and aid his development at different periods. They are all based upon
a natural evolution of physical and psychological powers that can be
only