74 MODERN IDEAS OF EVOLUTION 



then, and though I have since learnt much as 

 to the laws of light and the physiology of vision, I 

 have not yet fathomed the mysteries of the action of 

 light on nerve-cells and of the transmission of visual 

 impressions to the mind. The eye is indeed one of 

 those wonderful instances of correlation of distinct 

 and distant things which strike us so much in nature. 

 It embodies a vast variety of optical and vital struc 

 tures and powers, and through the medium of ethereal 

 undulations connects the sentient being with the 

 most distant luminous bodies in the universe. 



The eye even in its simplest form is a self-acting 

 and registering instantaneous photographic camera, 

 and having its plates so prepared as to represent 

 colours as well as forms, and it must to this end 

 possess at least a clear refractive medium, photo 

 graphic pigment-cells, and a nervous apparatus 

 capable of receiving the impressions produced and 

 conveying them to the sensorium. There must have 

 been a time when eyes did not exist. There may 

 have been a time after animals existed when none of 

 them possessed eyes. We have been informed by a 

 leading agnostic evolutionist that we may imagine 

 the eye to have originated spontaneously in some 

 low and simple form, and then by the operation of 

 infinite adjustments (through infinite time and with 

 out any adjuster) to have reached the perfection of 

 the eye of the eagle. Yet this is so little satisfactory 

 that we can well understand the saying of Darwin 



