32 NATURAL INHERITANCE. [chap. 



between an omnibus and a hansom, and it would be 

 difficult between an omnibus and a four-w T heeler. 



Evolution not by Minute Steps Only. — The theory 

 of Natural Selection might dispense with a restriction, 

 for which it is difficult to see either the need or the 

 justification, namely, that the course of evolution always 

 proceeds by steps that are severally minute, and that 

 become effective only through accumulation. That 

 the steps may be small and that they must be small are 

 very different views ; it is only to the latter that I 

 object, and only when the indefinite word " small " is used 

 in the sense of " barely discernible," or as small com- 

 pared with such large sports as are known to have been 

 the origins of new races. An apparent ground for the 

 common belief is founded on the fact that whenever 

 search is made for intermediate forms between widely 

 divergent varieties, whether they be of plants or of 

 animals, of weapons or utensils, of customs, religion or 

 language, or of any other product of evolution, a long 

 and orderly series can usually be made out, each member 

 of which differs in an almost imperceptible degree from 

 the adjacent specimens. But it does not at all follow 

 because these intermediate forms have been found to 

 exist, that they are the very stages that were passed 

 through in the course of evolution. Counter evidence 

 exists in abundance, not only of the appearance of con- 

 siderable sports, but of their remarkable stability in 

 hereditary transmission. Many of the specimens of 

 intermediate forms may have been unstable varieties, 



