Organic Connection Between Physical and Psychical 259 



lirginianus, repeated time after time in the early evening and 

 occasionally in midday when an approaching storm cools 

 the air, would seem to be another performance of the non- 

 adaptive sort. The suggestion that this is a courtship af- 

 fair can hardly stand, in view of the fact that at least as 

 often as otherwise the birds which do it are entirely alone. 

 Nor can one see how so extensive and swift a dive, with so 

 much noise, can be advantageous for the capture of flying 

 insects. 



And reflect on the quantity of movement of many ani- 

 mals. Can any one believe that mammals and lizards run, 

 birds and insects fly, and fishes swim just exactly so much as 

 and no more than, they must in order to survive? Would 

 it be contended that the Golden Plover, to take a well known 

 case of extensive migration, would certainly succumb in the 

 struggle for existence on arty thing less than a journey from 

 the high latitudes of the northern hemisphere well into the 

 southern hemisphere and back, each year? There is a vast 

 difference between a necessity for migration to some ex- 

 tent and a necessity for migration of a particular quantity. 

 One of the great weaknesses of the natural selection theory 

 has been, I am very sure, its slight regard for quantity ; 

 quantity of need, quantity of performance', quantity of 

 benefit. 



These examples serve to illustrate the fact that among 

 the higher animals at least, much muscular activity occurs 

 which is not at all, or only partly, adaptive. But by far the 

 more common occurrence of excessive activity is in connec- 

 tion with behavior which is more or less obviously adap- 

 tive. "A good thing carried to excess," in the familiar 

 phrase, expresses well what is in mind here. 



This excessiveness of adaptive activity is naturally more 

 easily recognized in animals which are most easily observed 

 and most active generally. Thus it is from birds and in- 

 sects that examples can be most readily drawn. 



