EXERCISES WITH AND WITHOUT APPARATUS. 627 
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statements. In what follows, please interpret all that is stated positively 
to be questions which I wish to present for your discussion. 
It makes little difference in the general or local hygienic results whether 
one takes an hour of routine gymnastics, involving all the muscles of the 
body, and without variation from year’s end to year’s end, or takes an 
aqual amount of exercise which constantly presents new codrdinative 
problems ; yet the development of power would be very different. The 
hygienic and educative results are so independent that I shall omit all 
mention of the former and limit myself purely to the latter. 
For years the feeling has prevailed that the nerve centers take a large 
cart in so-called muscular activity, but only recently has it been experi- 
mentally demonstrated. The evidence now seems to justify the belief 
that it is the actual fatigue of the nerve cells which limits muscular power ; 
that the muscle is not exhausted, even when it can be made to contract 
voluntarily no longer. Hodges’ brilliant work, showing the profound 
changes in structure resulting from motor nerve cell activity, is of the 
ntmost value to us, for it suggests the extreme power of adaptation 
possessed by the nerve cell, and probably the power to change quickly its 
way of reacting, thus demonstrating the physical basis of growth in skill. 
When a movement is made toward one’s eye, or a particle of dust is 
olown into it, the eyelid closes quickly ; and if the time interval between 
the stimulus and reaction is measured, it will be found to be a small frac- 
tion of a second. This is a type of a large class of movements which have 
been called reflex, because apparently the sensory stimulus is immediately 
reflected to the muscle, causing a contraction. The movements which are 
the result of such reflex actions always follow the stimuli after a short 
interval, and usually so as to protect the part stimulated. If the hand is 
iouched by a hot iror, it is snatched away from the iron even before we 
are conscious of being burned. This intelligent control of the muscles is 
not the result of brain action, and in fact takes place before the brain 
knows what has happened ; certainly before it could either help or hinder 
the movement. The movement follows the stimulus invariably ; it is 
tatal, it does itself. The nervous stimulus passes over a certain path 
called the reflex arc; beginning in the peripheral sense organ, it passes 
nward to the sensory nerve cells in the cord, then to selected motor 
nerve cells, and out to the corresponding muscles. There is a clear 
choice between many possible movements, and that one is selected which 
will best protect the individual. 
When a child sees a bright ball and reaches out for it, we have almost 
an identical process, only now the reaction to the stimulus is slower, and 
we say the child wills to pick up the ball. Here certain brain-cells are 
ased in addition to those of the cord, and the child is conscious of the 
ball and desires to possess it. ‘As such movements are studied, it is seen 
chat they are fatal, that the percention of the ball brings about the desire