EDUCATION AND CO-ORDINATION OF FUNCTION. 13 



him to follow your finger with his eyes from left to right and it 

 will be noted that the eyes will remain in the same axes until 

 the point is reached when the weakened muscle fails to contract, 

 then, as the finger travels to the right, the left eye will overshoot 

 the mark and look beyond the finger. This is due to the fact 

 that under usual circumstances there is an equal distribution of 

 energy sent into the co-ordinating muscles of the two eyes, but 

 whenever the point is reached where the weakened muscle 

 would come into action there is an immediate though un- 

 conscious access of energy distributed to both eyes, ineffective 

 so far as the faulty one is concerned, but causing its fellow to 

 receive so much that it travels too far. We see the same kind 

 of thing occasionally in cases of long- continued muscular spasm 

 which causes distortion of a foot. After the surgeon has 

 corrected the deformities, either by tendon or muscle trans- 

 plantation, or by simple shortening or lengthening, the effort 

 to use the newly-corrected limb sometimes causes a temporary 

 spasmodic deformity in its fellow, owing to an excess of energy 

 reaching the corresponding muscle. In both of these cases 

 education generally leads to recovery of function. In the case 

 of the squinting eye, the altered axes at first give rise to double 

 vision and other symptoms, which disappear as parts of the 

 retina not accustomed to act in concert learn to do so. In the 

 case of the limb, a transplanted muscle learns to take on a 

 function for which it was not originally intended and concerted 

 action becomes re-established ; were it not so, many of the 

 operations of this type for correction of deformity would be 

 unavailing. There is no difficulty in finding a variety of other 

 well-known types of disorder to illustrate the point that 

 conditions which promote the diversion of an unusual amount of 

 nerve energy in some given direction cause an upset in the 

 co-ordinative balance. We see it in some of the so-called habit 

 spasms. I saw a boy some years ago who was a source of great 

 anxiety to his people, and one of great interest to the inhabitants 



