58 POPULAR SCIENCE MONTHLY. 



existence, is extremely wasteful, and far from being as perfect as we 

 can easily imagine it might become if the process could be regulated 

 by individual selection. 



An Adaptation may be More Perfect than Survival requires. 



Are organisms ever more perfectly adapted in certain characters to 

 their environment than the demands of survival require? A positive 

 answer to this question might release us in part from the modern test 

 of utilitarianism. 



It is a well-known fact that through use many, perhaps all, parts 

 of the body are capable of doing more than they are called upon 

 to do during the ordinary life of the individual. The muscles through 

 practise not only become larger and stronger, but can even be edu- 

 cated to do more rapid work, as seen in the fingers of the skilled 

 pianist. The sensation of touch can be made more perfect through 

 practise. The skin thickens wherever continued pressure is brought to 

 bear on it. The bones will change their form, and even make new 

 sockets under suitable conditions. The walls of the blood vessels be- 

 come thicker if more blood is thrown into the blood channels. These 

 are typical examples of what the body is capable of doing, and the 

 responses in each case are obviously to the advantage of the individual. 

 What is the meaning of this power to do more than the ordinary 

 requirements of life demand? 



It has been suggested that the survival of the individual is some- 

 times determined by its capacity to rise to extreme occasions. For 

 example, the deer that is capable of putting on a little more speed than 

 its fellows, is the one that escapes. But this assumption fails to meet 

 fully the case, for, in the first place, it assumes as already present a 

 certain amount of the very quality to be explained. In the second 

 place a similar capacity is also present in other organs, in which it is 

 highly improbable that the power to improve somewhat could be of 

 sufficient importance to be decisive in a life and death struggle. It 

 could be of little advantage for instance to have the power of improving 

 the musical sense beyond a very low average, and no one will suppose 

 that this has been decisive in the evolution of the race. 



In other directions also we find an apparently superfluous perfection 

 of development. It is improbable that the extraordinary adjustments 

 of which the eye is capable have all been acquired little by little through 

 a life and death struggle. The eye is, however, such an important 

 organ for the welfare of the individual, that it is hard to demonstrate 

 positively that each stage was not of great use, but for the ear it seems 

 improbable that its perfection in certain respects could have been of 

 vital importance for the maintenance of the race. 



The symmetry of animals and of plants is also in many cases 



