A Rational and Humane Science 



of the most highly specialised objects in creation. 

 Helmholtz, as you know, is said to have remarked 

 concerning it that if an Optician had sent him an 

 instrument so defective he should have returned 

 it with his compliments. Helmholtz was a great 

 man, and I will not do him the injustice to suppose 

 that he did not know what he was saying. He 

 knew that, regarded as a machine for focussing 

 rays of light, the eye was decidedly defective ; 

 but then he knew well enough, doubtless, zvhy 

 it was defective — namely, because it is by no 

 means merely such a machine, but a great deal 

 more. 



The Eye, in fact, not only fulfils the action of 

 focussing rays of light — like an Opera Glass or 

 a Telescope — but it might be compared to another 

 instrument, a Photographic Camera, in respect 

 of the fact that it forms a picture of the outer world 

 which it throws on a sensitive plate at the back 

 — the Retina. But then, again, it is unlike any 

 of these " machines," in the fact that it was never 

 made by any Optician, human or divine, for any 

 one definite purpose. On the contrary, as we 

 know, it has grown, it has evolved ; it has come 

 down to us over the centuries, and over thousands 

 and thousands of centuries, from dim beginnings 

 in the lowliest organisms who first conceived the 

 faculty of Sight, continually modified, continually 

 shapen by small increments in various directions, 

 in accordance with the myriad needs of a myriad 

 creatures, living, some of them in water, some 

 of them in air, requiring some of them to see at 



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