RECAPITULATION AND CONCLUSION 425 



as we can judge, absolutely perfect ; and if some of 

 them be abhorrent to our ideas of fitness. We need 

 not marvel at the sting of the bee causing the bee's 

 own death ; at drones being produced in such vast 

 numbers for one single act, with the great majority 

 slaughtered by their sterile sisters ; at the astonishing 

 waste of pollen by our fir-trees ; at the instinctive 

 hatred of the queen bee for her own fertile daughters ; 

 at ichneumonidaB feeding within the live bodies of 

 caterpillars ; and at other such cases. The wonder 

 indeed is, on the theory of natural selection, that 

 more cases of the want of absolute perfection have not 

 been observed. 



The complex and little known laws governing varia- 

 tion are the same, as far as we can see, with the laws 

 which have governed the production of so-called specific 

 forms. In both cases physical conditions seem to have 

 produced but little direct effect ; yet when varieties 

 enter any zone, they occasionally assume some of the 

 characters of the species proper to that zone. In both 

 varieties and species, use and disuse seem to have pro- 

 duced some effect ; for it is difficult to resist this con- 

 clusion when we look, for instance, at the logger-headed 

 duck, which has wings incapable of flight, in nearly 

 the same condition as in the domestic duck ; or when 

 we look at the burrowing tucutucu, which is occasionally 

 blind, and then at certain moles, which are habitually 

 blind and have their eyes covered with skin ; or when 

 we look at the blind animals inhabiting the dark caves 

 of America and Europe. In both varieties and species 

 correlation of growth seems to have played a most im- 

 portant part, so that when one part has been modified 

 other parts are necessarily modified. In both varieties 

 and species reversions to long -lost characters occur. 

 How inexplicable on the theory of creation is the occa- 

 sional appearance of stripes on the shoulder and legs 

 of the several species of the horse-genus and in their 

 hybrids ! How simply is this fact explained if we 

 believe that these species have descended from a striped 

 progenitor, in the same manner as the several domestic 



