1 6 GERMINAL SELECTION. 



tageous, because it was necessary for the animal. 

 There is only one explanation possible for such patent 

 adaptations and that is selection. What is more, no 

 other natural way of their originating is conceivable, 

 for we have no right to assume teleological forces in 

 the domain of natural phenomena. 



I have selected the example of the butterfly's wing, 

 not solely because it is so widely known, but because 

 it is so exceedingly instructive, because we are still 

 able to learn so much from it. It has been frequently 

 asserted that the color-patterns of the butterfly's wings 

 have originated from internal causes, independently 

 of selection and conformably to inward laws of evo- 

 lution. Eimer has attempted to prove this assertion 

 by establishing in a division of the genus Papilio the 

 fact that the species there admit of arrangement in 

 series according to affinity of design. But is a proof 

 that the markings are modified in definite directions 

 during the course of the species's development equiv- 

 alent to a definite statement as to the causes that have 

 produced these gradual transformations? Or, is our 

 present inability to determine with exactness the bio- 

 logical significance of these markings and their modi- 

 fications, a proof that the same have no significance 

 whatever ? On the contrary, I believe it can be clearly 

 proved that the wing of the butterfly is a tablet on 

 which nature has inscribed everything she has deemed 

 advantageous to the preservation and welfare of her 

 creatures, and nothing else ; or, to abandon the sim- 

 ile, that these color-patterns have not proceeded from 

 inward evolutional forces, but are the result of selec- 

 tion. At least in all places where we do understand 

 their biological significance these patterns are consti- 

 tuted and distributed over the wing exactly as utility 

 would require. 



