284 PHYSICAL EXPKESSION. 



Given a description of the brain of a child two 

 years old, such as may indicate whether it be 

 healthy, we may conduct observations thus. As 

 regards its material structure we can gain but 

 little direct evidence. We can measure and take 

 note of the form and size of the skull, or brain- 

 case, and any changes occurring during the period 

 of observation ; we can test the special senses, 

 examine the optic nerve, etc. But these methods 

 of examination give us but little idea of the real 

 condition compared with the knowledge gained by 

 observing conditions of sleep (trophic) and con- 

 ditions of movement. The rhythmical successions 

 of sleep and of the recurrence of appetite for food, 

 are successions of trophic conditions, highly expres- 

 sive of health ; the movements of the child, the 

 coincidences of movements, and their series upon 

 stimulation teach us much more. It is, then, the 

 coincidences and successions of trophic and kinetic 

 action that give the best kind of expression. 



In a coincidence of movements many parts or 

 few may concur. In the growth of a body many or 

 few parts may grow at the same time. 



Now I will give some reasons why it is 

 desirable to give descriptions in this form. We 

 have ample proof that the coincidences of move- 

 ments are influenced by external forces : the sight 

 of an object and sounds can cause special series of 

 movements, this action makes it probable that 

 external forces regulate the series of trophic 

 actions. 



In studying examples of proportional develop- 



