OBJECTIONS TO THE THEORY OF DESCENT. 323 



polecats, on mice and land animals. If a different case 

 had been taken, and it had been asked how an insectivor- 

 ous quadruped could possibly have been converted into 

 a flying bat, the question would have been far more diffi- 

 cult to answer. Yet I think such difficulties have little 

 weight. 



Here, as on other occasions, I lie under a heavy dis- 

 advantage, for, out of the many striking cases which I 

 have collected, I can give only one or two instances of 

 transitional habits and structures in allied species ; and 

 of diversified habits, either constant or occasional, in the 

 same species. And it seems to me that nothing less than 

 a long list of such cases is sufficient to lessen the difficulty 

 in any particular case like that of the bat. 



WHY NATUEE TAKES NO SUDDEN LEAPS. 



Origin of Finally, then, although in many cases it is 



Species, most difficult even to conjecture by what tran- 

 sitions organs have arrived at their present 

 state, yet, considering how small the proportion of liv- 

 ing and known forms is to the extinct and unknown, I 

 have been astonished how rarely an organ can be named, 

 toward which no transitional grade is known to lead. It 

 certainly is true that new organs, appearing as if created for 

 some special purpose, rarely or never appear in any being 

 — as indeed is shown by that old but somewhat exagger- 

 ated canon in natural history of " Xatura non facit sal- 

 tum." We meet with this admission in the writings of al- 

 most every experienced naturalist ; or as Milne-Edwards 

 has well expressed it, Nature is prodigal in variety, but 

 niggard in innovation. Why, on the theory of Creation, 

 should there be so much variety and so little real novelty ? 

 Why should all the parts and organs of many independ- 



