i ORTHOGENESIS 75 



nature. From the fact that an orator falls in, at first, 

 with the passions of his audience in order to make 

 himself master of them, it will not be concluded that to 

 follow is the same as to lead. Now, living matter 

 seems to have no other means of turning circumstances 

 to good account than by adapting itself to them 

 passively at the outset. Where it has to direct a 

 movement, it begins by adopting it. Life proceeds 

 by insinuation. The intermediate degrees between a 

 pigment-spot and an eye are nothing to the point : 

 however numerous the degrees, there will still be 

 the same interval between the pigment-spot and the 

 eye as between a photograph and a photographic 

 apparatus. Certainly the photograph has been gradu 

 ally turned into a photographic apparatus ; but could 

 light alone, a physical force, ever have provoked this 

 change, and converted an impression left by it into a 

 machine capable of using it ? 



It may be claimed that considerations of utility are 

 out of place here ; that the eye is not made to see, but 

 that we see because we have eyes ; that the organ is 

 what it is, and &quot; utility &quot; is a word by which we 

 designate the functional effects of the structure. But 

 when I say that the eye &quot; makes use of&quot; light, I do not 

 merely mean that the eye is capable of seeing ; I allude 

 to the very precise relations that exist between this 

 organ and the apparatus of locomotion. The retina of 

 vertebrates is prolonged in an optic nerve, which, again, 

 is continued by cerebral centres connected with motor 

 mechanisms. Our eye makes use of light in that it 

 enables us to utilize, by movements of reaction, the 

 objects that we see to be advantageous, and to avoid 

 those which we see to be injurious. Now, of course, 

 as light may have produced a pigment-spot by physical 



