248 THE ZOOLOGIST. 



examples of mutants, which appear to be chiefly based on 

 variations of Mus rattus, are, as usual, quite fertile with the 

 parent form. 



I am unable to discover where a variant ends and a mutant 

 begins, although one can understand the difference in the main. 

 It appears probable that this ambiguity may be likened to the 

 difference visible in white and negro, but indefinable in their 

 cross-breeds, and also to the graduating difference between 

 species where no line can be drawn. 



If we instance Cebus Monkeys, Roan Antelopes, and Eed 

 Deer only, I think it will prove a matter of some difficulty to 

 distinguish the mutants from the variants. There seems 

 evidence to show evolution of these and similar wild forms by 

 variation, as in domestic types. 



How does the big ankle of the St. Kilda islanders arise ? 

 Also the long legs of the Dinka tribes? As mutations? I 

 should imagine not. And are these not acquired ? An argu- 

 ment in favour of acquired characters not being passed on 

 is that of the non-transmission of docked tails in Dogs. 

 This, however, is mere mutilation. Nature would hardly in- 

 spire the deprived parent, handicapped in its efforts to balance 

 itself, to transmit such a deformity to its unborn young. 



Although where Natural Selection gets a chance to work 

 fairly (as conceived theoretically by the Darwinians), one might 

 expect it to do its work and thus obviate the necessity for 

 sudden mutations, it is possible it does not invariably get this 

 opportunity. 



The selection that goes on must depend much on chance, 

 namely, disease, famine, battle, murder, and accident, with the 

 best types perhaps killed off. At the best these must be liable 

 to be modified by crossing with bad types, and thus the race in 

 desperation may have to throw off sudden big jumps (mutations) 

 of much better survival value in order to exist ; in fact, to make 

 the jump in spite of the selection it has undergone and not 

 through it. Natural Selection must have a better chance of 

 acting on big jumps (mutations) than on slight differences 

 (variations). 



Is it not possible that, whereas we may style such evolutions 

 as change of colour from grey to black, absence of horns in 



