Appendix II. 325 



Here is another passage to the same geneial effect. In 

 alluding to the objection from inutility as advanced by 

 Bronn, Broca, and Nageli, Mr. Darwin says : — " There is 

 much force in the above objection"; and, after again 

 pointing out the important possibility in any particular 

 cases of hidden or former use, and the action of the laws of 

 growth, he goes on to say, — " In the third place, we have 

 to allow for the direct and definite action of changed con- 

 ditions of life, and for so-called spontaneous variations, in 

 which the nature of the conditions plays quite a sub- 

 ordinate part ^" Elsewhere he says, — " It appears that I 

 formerly underrated the frequency and value of these latter 

 forms of variation as leading to permanent modifications of 

 structure independeJitly of natural selection ^" The " forms of 

 variation " to which . he here alludes are " variations which 

 seem to us in our ignorance to arise spontaneously"; and 

 it is evident that such variations cannot well " arise " in 

 two or more species of a genus similarly and simultane- 

 ously, so as independently to lead " to permanent modifica- 

 tions of structure " in two or more parallel lines. It is 

 further evident that by "spontaneous variations" Darwin 

 alludes to extreme cases of spontaneous departure from 

 the general average of specific characters; and therefore 

 that lesser or more ordinary departures must be of still 

 greater " frequency." 



Again, speaking of the principles of classification, 

 Darwin writes : — 



" We care not how trifling a character may be— let it be the 

 mere inflection of the angle of the jaw, the manner in which 



In criticising that paper in Nature (vol. xxxix. p. \^i),■ Mr. Thiselton 

 Dyer says of my interpretation of this passage, " the obvious drift of this 

 does not relate to specific differences, but to those which are charac- 

 teristic of family." But in making this remark Mr. Dyer could not 

 have read the passage with sufficient care to note the points which I have 

 now explained. 



^ Origin of Species, p. 171. • t^i<i- P- 421. 



