48 Arrangement and Formation of the Series. [CHAP. 11. 



rower. Nor is there any reason to suppose that the same 

 process of subdivision could not be carried out as much 

 farther as we chose to prolong it. 



19. It need hardly be added to the above -remarks 

 that no one who gives the slightest adhesion to the Doctrine 

 of Evolution could regard the type, in the above qualified 

 sense of the term, as possessing any real permanence and 

 fixity. If the constant causes, whatever they may be, re 

 main unchanged, and if the variable ones continue in the 

 long run to balance one another, the results will continue to 

 cluster about the same mean. But if the constant ones 

 undergo a gradual change, or if the variable ones, instead of 

 balancing each other suffer one or more of their number to 

 begin to acquire a preponderating influence, so as to put a 

 sort of bias upon their aggregate effect, the mean will at 

 once begin, so to say, to shift its ground. And having once 

 begun to shift, it may continue to do so, to whatever extent 

 we recognize that Species are variable and Development is a 

 fact. It is as if the point on the target at which we aim, in 

 stead of being fixed, were slowly changing its position as we 

 continue to fire at it; changing almost certainly to some ex 

 tent and temporarily, and not improbably to a considerable 

 extent and permanently. 



20. Our examples throughout this chapter have been 

 almost exclusively drawn from physical characteristics, 

 whether of man or of inanimate things; but it need not be 

 supposed that we are necessarily confined to such instances. 

 Mr Galton, for instance, has proposed to extend the same 

 principles of calculation to mental phenomena, with a view 

 to their more accurate determination. The objects to be 

 gained by so doing belong rather to the inferential part of 

 our subject, and will be better indicated further on; but 

 they do not involve any distinct principle. Like other at- 



