858 OBJECTIONS TO THE THEOKY [Chap. Vm. 



modifications of structure could have been slowly accu- 

 mulated bv natural selection. 



This difficulty, though appearing insuperable, is 

 lessened, or, as I believe, disappears, when it is remem- 

 bered that selection may be applied to the family, as 

 well as to the individual, and may thus gain the desired 

 end. Breeders of cattle wish the flesh and fat to be 

 well marbled together : an animal thus characterised 

 has been slaughtered, but the breeder has gone with 

 confidence to the same stock and has succeeded. Such 

 faith may be placed in the power of selection, that a 

 breed of cattle, always yielding oxen with extraordinarily 

 long horns, could, it is probable, be formed by care- 

 fully watching which individual bulls and cows, when 

 matched, produced oxen with the longest horns ; and yet 

 no one ox would ever have propagated its kind. Here 

 is a better and real illustration : according to M. Verlot, 

 some varieties of the double annual Stock from having 

 been long and carefully selected to the right degree, 

 always produce a large proportion of seedlings bearing 

 double and quite sterile flowers ; but they likewise yield 

 some single and fertile plants. These latter, by which 

 alone the variety can be propagated, may be compared 

 with the fertile male and female ants, and the double 

 sterile plants with the neuters of the same community. 

 As with the varieties of the stock, so with social 

 insects, selection has been applied to the family, and 

 not to the individual, for the sake of gaining a sendee- 

 able end. Hence we may conclude that slight modi- 

 fications of structure or of instinct, correlated with 

 the sterile condition of certain members of the com- 

 munity, have proved advantageous : consequently the 

 fertile males and females have flourished, and trans- 



