WHA T WE MIGHT EXP EC T. 193 



Darwin, though apparently of opinion that the tendency 

 to do this has been much exaggerated, yet does not 

 doubt that such a tendency exists, as shown by well 

 authenticated instances. He writes: "It has been 

 repeatedly asserted in the most positive manner by 

 various authors that feral animals and plants invariably 

 return to their primitive specific type." 



This shows, at any rate, that there is a considerable 

 opinion to this effect among observers generally. 



He continues : " It is curious on what little evidence 

 this belief rests. Many of our domesticated animals 

 could not subsist in a wild state," — so that there is no 

 knowing whether they would or would not revert. 

 " In several cases we do not know the aboriginal parent 

 species, and cannot tell whether or not there has been 

 any close degree of reversion." So that here, too, there 

 is at any rate no evidence against the tendency ; the 

 conclusion, however, is that, notwithstanding the defi- 

 ciency of positive evidence to warrant the general 

 belief as to the force of the tendency, yet " the simple 

 fact of animals and plants becoming feral does cause 

 some tendency to revert to the primitive state," and he 

 tells us that " when variously- coloured tame rabbits are 

 turned out in Europe, they generally re-acquire the col- 

 ouring of the wild animal ; " there can be no doubt," he 

 says, " that this really does occur," though he seems in- 

 clined to account for it by the fact that oddly-coloured 

 and conspicuous animals would suffer much from beasts 

 of prey and from being easily shot. " The best known 

 case of reversion," he continues, "and that on which 

 the widely-spread belief in its universality apparently 



