60 THE MEANING OF EVOLUTION 



behavior of the animal world. It is difficult to prove 

 that there is going on under our eyes a steady and 

 real improvement in the adaptation of the animals and 

 plants around us to the situation in which they are 

 placed. As far back as man's memory runs they 

 seem to have been about what they now are; as far 

 even as man's historical record runs they seem to have 

 suffered no great alteration. The Egyptian of the old 

 tombs is much like the Egyptian of the same rank 

 to-day. The African of the tombs has the African 

 features of to-day. Under such circumstances it is 

 hard to prove that there is a steady and undoubted 

 advance. For the most part the balance of the ani- 

 mal world is fairly even, and any species does not 

 ordinarily change rapidly enough or migrate widely 

 enough to show us its new features. It is difficult to 

 see the struggle which we are so sure is going on. 

 The life of animals is so hidden in many of its de- 

 tails that their joys and sorrows, if such we may call 

 them, scarcely fall under our observation. Now and 

 then an opportunity comes to see the process of adap- 

 tation work itself out. The struggle for existence be- 

 gins anew and is carried on with special vigor, with 

 victory, temporary or permanent, to one of the par- 

 ticipants in the struggle. 



The opportunity to observe such a change is pre- 

 sented in the United States by the introduction of the 



