62 EVOLUTION, SOCIAL AND ORGANIC 



another the same length, while the third has a 

 longer neck — over five feet. 



Now comes the struggle for existence. When 

 this family of giraffes is fairly grown and the 

 new-comers are approaching breeding age — 

 mark the importance of this matter of 

 "breeding age," for the problem is to find out 

 how nature determines which shall be bred 

 from — they are obliged to forage for them- 

 selves. There is no pasture to graze; they 

 live in what is almost a desert. There are few 

 shrubs; scarcely anything but fairly high 

 trees — from ten to twenty feet. If a giraffe 

 breeder had this matter in hand and he wished 

 to increase the length of the giraffe's neck, the 

 problem would be simple. He would select 

 number three with the longest neck, pair it 

 with the longest necked member of the op- 

 posite sex in some other family and the trick 

 would be done. But this is in Central Africa, 

 where there is no breeder to interfere, and the 

 question is: can nature accomplish the same 

 result without his help? 



This is what happens. First the leaves are 

 eaten from all the lower branches as they are 

 reached with the least effort. Then they go 

 higher and still higher until the point is 

 reached where number one with the shortest 

 neck cannot reach any further and the terrible 



