26 De Vi Physica 



answer which only shows how curiously 

 unable he was to see the point of his own 

 theory. Putting aside the ignoratio elenchi 

 for even if there are gradations in eyes, that 

 does not prove in the least degree, that they 

 came about by ' Natural Selection,' the 

 irrelevance and futility of the reply escaped 

 his attention, simply by reason of this par- 

 ticular instance. With many organs it is 

 not readily apparent, because it is not ob- 

 vious that in an incipient state they would 

 involve the instant death of their owner. 

 But the truth is beyond denial in the case 

 before us. How could any hippopotamus 

 exist under water for a moment with an 

 ' incipient J nostril ? It is obvious that a 

 ' hole ' cannot begin gradually : the moment 

 that there is a hole, there is a hole : the 

 water must rush in. Nostrils that open in 

 air, and close in water, could not possibly 

 originate gradually : they must have arisen 



