Characters as Adaptive and Specific. 189 



occasionally appear in all the long-eared races, but are not 

 strictly inherited, for they occur or fail in the animals of the 

 same litter. As no wild pigs are known to have analogous 

 appendages, we have at present no reason to suppose that their 

 appearance is due to reversion ; and if this be so, we are forced 

 to admit that a somewhat complex, though apparently useless, 

 structure may be suddenly developed without the aid of 

 selection '.' " 



To this case Mr. Wallace objects : — 



"But it is expressly stated that they are not constant; they 

 appear 'frequently' or 'occasionally,' they are 'not strictly 

 inherited, for they occur or fail in animals of the same litter ' : 

 and they are not always symmetrical, sometimes appearing on 

 one side of the face alone. Now, whatever may be the cause 

 or explanation of these anomalous appendages, they cannot be 

 classed with 'specific characters,' the most essential features 

 of which are, that they are symmetrical, that they are inherited, 

 and that they are constant V 



But, to begin with, I have not classed these ap- 

 pendages with " specific characters," nor maintained 

 that Normandy pigs ought to be regarded as specifi- 

 cally distinct on account of them. What I said 

 was : — 



" Now, if any such structure as this occurred in a wild species, 

 and if any one were to ask what is the use of it, those who rely 

 on the argument from ignorance would have a much stronger 

 case than they usually have ; for they might point to the 

 cartilage supplied with muscles, and supporting a curious 

 arrangement of bristles, as much too specialized a structure to 

 be wholly meaningless. Yet we happen to know that this 

 particular structure is wholly meaningless V 



* Variation, &c. vol. i. pp. 78-79. ' Darwinism, pp. 139-40. 



* Mr. Wallace deems the concluding words "rather confident." 

 I was not, however, before aware that he extended his a priori views on 



