TELEOLOGICAL EVOLUTION OF ORGANISM. 49 



bird found itself in some small difficulty, out of which 

 it either saw, or at any rate found that it could ex- , 

 tricate itself by striking out vigorously with its feet 

 and extending its toes as far as ever it could ; it thus 

 began to learn the art of swimming and conceived the 

 idea of swimming synchronously, or nearly so; or 

 perhaps wishing to get over a yard or two of deep 

 water, and trying to do so without being at the trouble 

 of rising to fly, it would splash and struggle its way 

 over the water, and thus practically swim, though 

 without much perception of what it had been doing. 

 Finding that no harm had come to it, the bird would 

 do the same again, and again ; it would thus presently 

 lose fear, and would be able to act more calmly ; then 

 it would begin to find out that it could swim a little, 

 and if its food lay much in the water so that it would 

 be of great advantage to it to be able to alight and 

 rest without being forced to return to land, it would 

 begin to make a practice of swimming. It would now 

 discover that it could swim the more easily according 

 as its feet presented a more extended surface to the 

 water ; it would therefore keep its toes extended when- 

 ever it swam, and as far as in it lay, would make the 

 most of whatever skin was already at the base of its 

 toes. After very many generations it would become 

 web-footed, if doing as above described should have 

 been found continuously convenient, so that the bird 

 should have continuously used the skin about its toes 

 as much as possible in this direction. 



For there is a margin in every organic structure 

 (and perhaps more than we imagine ia things inor- 



