CHAPTER XIII 



PROBLEMS OF THE DISTRIBUTION OF THE EAST AFRICAN 

 FLORA AND FAUNA 



" Kisauni kutamea mvinde ? " 

 " Mvita kutamea mgomba? " 



(Will Kisauni grow the she-oak? 

 Will Mombasa grow the banana tree ?) 



Zanzibar i F?-overbs. 



The problems of the distribution of animals and plants in a 

 country are riddles, the difficulty of which varies with the 

 complexity of its history. In regions of great stability they 

 are simpler than where important geographical and climatic 

 changes have taken place in the past. Thus, on the old 

 view of the geological uniformity of the continent of Africa, 

 these problems might have been expected to be com- 

 paratively simple, whereas they have always proved excep- 

 tionally confused and intricate. After making a preliminary 

 collection in East Africa, I compared notes with those of the 

 residents, such as Mr. Ainsworth of Machakos, the late Mr. 

 Bell Smith of Melindi, and the late Dr. Charters of Kibwezi, 

 who had had experience on the west coast. The result 

 sorely puzzled me, by bringing out apparently glaring con- 

 tradictions in the facts of distribution. Thus certain groups 

 run across Africa from east to west, while others extend from 

 north to south. The commoner beetles, butterflies, and birds 

 seemed to belong to a fauna that spread across the continent 

 from the Atlantic to the Indian Ocean. On the other hand, 

 some less important groups of animals, and some of the more 

 striking of the plants, have their nearest affinities with those of 



