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should in reality be gifted with stronger powers of flight 

 (rather than weaker ones), to fortify them against such 

 disasters ; and that, consequently, the above phenomena 

 are not explicable on Mr. Darwin's hypothesis. For my 

 own part, I am inclined to accept that theory, in all its 

 fullness ; and, furthermore, I do not believe that the latter 

 consideration (though it unquestionably contains much 

 presumptive truth) does at all interfere with the admission 

 of it, seeing that either requirement may be fulfilled, 

 according to the nature of the several species which are 

 destined to be acted upon. Thus, if flight is absolutely 

 indispensable, as in the greater number of the Lepido- 

 ptera, and beetles of a flower-infesting tendency, we shall 

 find that the wings remain unaltered (if indeed they be 

 not actually increased in capacity, of which I am by no 

 means certain), and that the effect of isolation is more 

 particularly evident in a diminution of stature. But if, 

 on the contrary, the creatures are less dependent on 

 aerial progression for their sustenance, as in the pre- 

 dacious tribes generally, especially those of nocturnal 

 habits, the reduced area in which they are confined, in 

 conjunction, it may be, with the danger to which they 

 would constantly expose themselves by the promiscuous 

 employment of organs which their modes of life do not 

 positively need, would seem to render the presence of 

 wings unnecessary; and they are accordingly, by degrees, 

 removed : in which case, however, a compensation for 

 the loss is not unfrequently granted by an increase (more 

 or less perceptible) in bulk. 



