50 CONCLUSION 



with races; it is to compare the effects of crossing 

 them. Would it not be wonderful, if the union of 

 two organisms, produced by two separate acts of 

 Creation, blended their characters together when 

 crossed according to the same rules, as two races 

 which have undoubtedly descended from same 

 parent stock; yet this can be shown to be the 

 case. For sterility, though a usual {?), is not an 

 invariable concomitant, it varies much in degree 

 and has been shown to be probably dependent on 

 causes closely analogous with those which make 

 domesticated organisms sterile. Independent of 

 sterility there is no difference between mongrels 

 and hybrids, as can be shown in a long series of 

 facts. It is strikingly seen in cases of instincts, 

 when the minds of the two species or races become 

 blended together 1 . In both cases if the half-breed 

 be crossed with either parent for a few generations, 

 all traces of the one parent form is lost (as Kolreuter 

 in two tobacco species almost sterile together), so 

 that the Creationist in the case of a species, must 

 believe that one act of creation is absorbed into 

 another ! 



CONCLUSION. 



Such are my reasons for believing that specific 

 forms are not immutable. The affinity of different 

 groups, the unity of types of structure, the repre- 

 sentative forms through which foetus passes, the 

 metamorphosis of organs, the abortion of others 

 cease to be metaphorical expressions and become 

 intelligible facts. We no longer look (an) on animal 

 as a savage does at a ship 2 , or other great work of 

 art, as a thing wholly beyond comprehension, but we 



1 " A cross with a bull-dog has affected for many generations the courage 

 and obstinacy of greyhounds," Origin, Ed. i. p. 214, vi. p. 327. 



2 The simile of the savage and the ship occurs in the Origin, Ed. i. 

 p. 485, vi. p. 665. 



