BUSHBUCKS, KOODOOS, AND ELANDS 473 



cealing value whatever. They are probably gradually dis- 

 appearing; they diminish the farther the animals are found 

 from the probable original centre of development in the Middle 

 African forests; and in the form farthest from this, the South 

 African form, which has certainly been the last to be dif- 

 ferentiated, the stripes have completely disappeared. This 

 of course means that they have no concealing value such 

 as to make them in even the slightest degree a factor 

 in securing through natural selection the survival of the 

 wearer under the conditions of the existing environment. 

 The eland is certainly less plentiful than the other antelopes 

 which possess a more advertising coloration; and it is more 

 shy, and, instead of seeking to elude observation, prefers to 

 station itself where it can detect its foes at a distance and 

 run off. If the color of its coat were of benefit to it, it would 

 certainly act so as to get that benefit, and this it never does. 

 Evidently its coloration is an entirely negligible factor so far 

 as its survival is concerned. 



The East African race differs very little from livingstonii 

 of the Zambesi Valley. It may be distinguished usually by 

 darker coloration and longer head, but the difference is 

 merely an average affair. The race was based by Lydekker 

 upon a specimen showing white chevrons on the snout and 

 a narrow bush on the forehead. These characters are, how- 

 ever, juvenile, and are as prevalent in the immature eland 

 of Mashonaland as they are in British East Africa. The old 

 males in East Africa have the entire forehead covered with 

 a heavy mat of hair and lack the white chevrons bordering 

 the mat on the snout, as do also the old males from the Zam- 

 besi. Two bulls shot from the same herd on the Loita 

 Plains by Colonel Roosevelt show both styles of coloration. 

 The younger bull, which was a fully grown animal, had the 

 narrow bush of hair on the forehead and white chevrons on 

 the snout, while the aged bull of the same body size had the 



