178 BIOLOGY: GENERAL AND MEDICAL 



a succession of semi-automatic movements is initiated. 

 Thus, you first rise from your chair, then put on your 

 hat, then open the door, then walk through the garden, 

 and then pluck the rose which you place in your button- 

 hole. Each of these acts is semi-automatic because it 

 can be performed semi-consciously, that is, without 

 special attention, having so often been performed before 

 as to have become thoroughly coordinated. Who 

 thinks what he is doing as he walks along the street? 

 The action is thoroughly coordinated and purely auto- 

 matic, but it is not so with the infant learning to walk, 

 and it is not so with some new method of progress, as, 

 for example, walking upon stilts or gliding upon skates. 

 An adult learning such tricks is painfully conscious of 

 the lack of the proper coordination for the required 

 movements. 



Presumably the automatic movement has the same 

 foundation as the thought. Each is a cell memory. A 

 cell or group or cells, having been once impressed, recalls 

 the same impression and passes it around in the same 

 manner, producing definite impressions upon group after 

 group. The act of walking is not simple; the move- 

 ments of the limbs in balancing the heavy body as its 

 centre of gravity is alternately disturbed and recovered, 

 is extremely complicated, and necessitates the combined 

 efforts of many muscles brought into action singly or in 

 combination in orderly sequence. Yet this can be 

 achieved without conscious thought, because through 

 long practice the cells remember the lessons they have 

 learned and carry them through without a mistake. 

 How complicated is the performance of a fine pianist! 

 Does he know each note struck? Not at all; the whole 

 is a series of wonderfully well-coordinated, highly com- 

 plex, automatic acts resulting from the precise activity of 

 well-trained nerve cells whose memories do not fail. 

 How difficult to learn the piano where the eye reading 

 the notes and signs and the fingers interpreting them 

 must work in harmony! With what tears and pains 

 does the child learn to drum some simple composition! 



