158 MISCELLANEOUS OBJECTIONS TO THE [CHAP. VII. 



selection or the survival of the fittest, which implies that when 

 variations or individual differences of a beneficial nature happen 

 to arise, these will be preserved ; but this will be effected only 

 under certain favourable circumstances. 



The celebrated palaeontologist, Bronn, at the close of his German 

 translation of this work, asks, how, on the principle of natural 

 selection, can a variety live side by side with the parent species ? 

 If both have become fitted for slightly different habits of life or 

 conditions, they might live together ; and if we lay on one side 

 polymorphic species, in which the variability seems to be of a 

 peculiar nature, and all mere temporary variations, such as size, 

 albinism, &c., the more permanent varieties are generally found, 

 as far as I can discover, inhabiting distinct stations, such as 

 high land or low land, dry or moist districts. Moreover, in the 

 case of animals which wander much about and cross freely, their 

 varieties seem to be generally confined to distinct regions. 



Bronn also insists that distinct species never differ from each 

 other in single characters, but in many parts ; and he asks, how it 

 always comes that many parts of the organisation should have 

 been modified at the same time througli variation and natural 

 selection ? But there is no necessity for supposing that all the 

 parts of any being have been simultaneously modified. The most 

 striking modifications, excellently adapted for some purpose, might, 

 as was formerly remarked, be acquired by successive variations, if 

 slight, first in one part and then in another ; and as they would be 

 transmitted all together, they would appear to us as *if they had 

 been simultaneously developed. The best answer, however, to the 

 above objection is afforded by those domestic races which have 

 been modified, chiefly through man's power of selection, for some 

 special purpose. Look at the race and dray horse, or at the grey- 

 hound and mastiff. Their whole frames and even their mental 

 characteristics have been modified; but if we could trace each 

 step in the history of their transformation, and the latter steps 

 can be traced, we should not see great and simultaneous changes, 

 but first one part and then another slightly modified and improved. 

 Even when selection has been applied by man to some one 

 character alone, of which our cultivated plants offer the best 

 instances, it will invariably be found that although this one part, 

 whether it be the flower, fruit, or leaves, has been greatly changed, 

 almost all the other parts have been slightly modified. This may 

 be attributed partly to the principle of correlated growth, and 

 partly to so-called spontaneous variation. 



A much more serious objection has been urged by Bronn, and 

 recently by Broca, namely, that many characters appear to be of 

 no service whatever to their possessors, and therefore cannot have 

 been influenced through natural selection. Bronn adduces the 



