NATURAL SELECTION CRITICISED. 279 



it ? With such an if it is easy for us imaginatively to 

 deceive ourselves. What is gradation ? and what are 

 its 'powers ? Of course, it is understood that these 

 questions are limited here to what concerns life, and the 

 organs and organisms of life. Gradation quantitatively, 

 qualitatively, or quantitativo-qualitively, is a wide matter, 

 and not in the question at present. There are gradations 

 of homogeneous quality motion, for example which to 

 us are absolutely inconceivable. Say light travels at the 

 rate of 200,000 miles in a second, we cannot in any 

 way mentally image, such a fact. Suppose the Channel 

 to be a gap of twenty miles, is it conceivable that if we 

 were as swift as light, we could pass from England to 

 France and back again five thousand times in a pulse- 

 beat ? When the wind blows at the rate of a hundred 

 miles an hour, it is called a hurricane, and it tears up 

 trees, levels houses to the ground, etc. etc. If it is so 

 violently destructive at less than a mile in a second, 

 what would be the result if it moved even 20,000 times 

 less swift than light ? It would certainly blow the 

 Atlantic into the clouds, with the Pacific to follow. 

 Rather it is simply impossible. Conditions must cohere 

 with conditions ; and for such a tempest on the globe, 

 the conditions on this side and on that are utterly 

 incoherent. 



From these and other the like infinitely possible 

 calculations, it is evident that there must be allowed 

 some consideration of correlative conditions as mutually 

 compatible before we can accept the terms of conception 

 or imagination which we see Mr. Darwin at once give 

 himself. He cannot, he says, set bounds to the possible 

 production of any the most exquisite structure, on the 

 part of natural selection, if only " such structure can 

 be arrived at by gradation ; " and we see now that there 

 are necessary limitations to gradation in homogeneous 



