272 THE KIDDLE OF THE UNIVEESE. 



Neither the old mystic vitalism nor the new, equally 

 irrational, neovitalism can give any explanation of 

 these and many other purposeless contrivances in the 

 structure of the plant and the animal ; but they are 

 very simple in the light of the theory of descent. It 

 shows that these rudimentary organs are atrophied, 

 owing to disuse. Just as our muscles, nerves, and 

 organs of sense are strengthened by exercise and 

 frequent use, so, on the other hand, they are liable to 

 degenerate more or less by disuse or suspended 

 exercise. But, although the development of the 

 organs is promoted by exercise and adaptation, they 

 by no means disappear without leaving a trace after 

 neglect ; the force of heredity retains them for many 

 generations, and only permits their gradual dis- 

 appearance after the lapse of a considerable time. 

 The blind " struggle for existence between the organs " 

 determines their historical disappearance, just as it 

 effected their first origin and development. There is 

 no internal " purpose " whatever in the drama. 



The life of the animal and the plant bears the same 

 universal character of incompleteness as the life of 

 man. This is directly attributable to the circum- 

 stance that nature — organic as well as inorganic — is 

 in a perennial state of evolution, change, and trans- 

 formation. This evolution seems on the whole — at 

 least as far as we can survey the development of 

 organic life on our planet — to be a progressive 

 improvement, an historical advance from the simple 

 to the complex, the lower to the higher, the imperfect 

 to the perfect. I have proved in my General 

 Morphology that this historical progress — or gradual 

 perfecting (teleosis) — is the inevitable result of selec- 

 tion, and not the outcome of a preconceived design. 



