190 EASTERN ETHIOPIA xv 



Zebras are, in a sense, a pest ; wandering over the 

 plain, they Ijreak down fences and trample ovei' culti- 

 vated areas. They are good friends with ostriches, 

 harteheests, and Thomson's gazelles. The hartebeests 

 are the friends and guides of zebras, and the latter 

 never neoiect the sentinel's sio-nal of alarm. 



Zebras will disappear before the march of civilisation ; 

 the lion takes a heavy toll of them, but the settler is 

 the bigger foe. In the grass land around Nakuru we 

 saw their skeletons in abundance picked clean by 

 vultures and bleached by sun and weather. 



The presence of so many zehnx skeletons in the grass- 

 covered crater-like depressions around Nakuru recalled 

 to my mind a fact often referred to by geologists, 

 namely, the great accumulation of mammalian bones in 

 a limited area. Sometimes the bones are those of the 

 same species of vertebrate animal, or they may be a 

 mixture of incongruous species. Several explanations 

 have been advanced to account for such local collections 

 of skeletons. 



Darwin, in his delightful accouirt of the voyage of the 

 Beagle refers to this in regard to the Guanaco, for he 

 writes that they have particular spots for lyiug down 

 to die, and that in certaiir circumscribed spots on the 

 l)anks of the St. Cruz river the ground was actually 

 white with Itones. He particularly examined the bones 

 and points out that they were not gnawed or broken. 

 He came to the conclusion that " the animals in most 

 cases must have crawded, before dying, beneath and 

 amongst the bushes." Darwin also mentions that at St. 

 Jago in the Cape de Verd Islands he found, in a ravine, 

 a retired corner covered with bones of the goat, and 

 exclaimed that it was the burial "'round of all goats 

 in the island. 



It appears that the Swahili traders believe in 

 natural " animal cemeteries " ; Major Powell-Cotton 

 describes one which he visited near Mount Zunut in the 

 Toposa Country. He was surprised to hnd the whole 



