TRANSMUTABLE. 139 



The next heading of Mr. Darwin, on the 

 "Difficulties on Theory," is 



3. Organs of extreme perfection and compli- 

 cation. The eye naturally comes under notice 

 first, for, as Mr. Darwin candidly observes, to 

 suppose that it could be formed "by natural 

 selection, appears absurd in the highest degree." 



He does not, however, flinch from a bold effort 

 to solve the difficulty, for he says further on, 

 under the inspiration of the natural selection 

 doctrine, that the difficulty, though "insuperable 

 by our imagination, can hardly be considered 

 real ;" and it is illustrated by the following state- 

 ment: "How a nerve conies to be sensitive to 

 light, hardly concerns us more than how life itself 

 first originated; but I may remark that several 

 facts make me suspect that any sensitive nerve 

 may be rendered sensitive to light, and likewise to 

 those coarser vibrations of the air, which produce 

 sound" 



But what does Mr. Darwin mean by light? 

 th'ere is all the difference in the world between 

 the objective light of the physicist and the sub- 

 jective light of the physiologist. The latter, which 

 is the consciousness of the former, is what con- 

 cerns us more especially in dealing with the eye. 

 If the retina were spread out on the face, a sheet 

 of light might be perceived, but no objects. But 

 suppose an arrangement of lenses, so arranged as 

 to converge these rays to a point, and all the 

 pencils of a body to corresponding points, we have 

 a picture of the object on that point, from which 



