X PREFACE 



months' field work, almost every day of which was devoted 

 to active operations. More recently, in 191 1 and 1912, 

 Edmund Heller again traversed much of the same highland 

 country in British East Africa with Paul J. Rainey. In 

 addition to the regions previously visited he journeyed into 

 the desert district lying between the Northern Guaso Nyiro 

 River and Mount Marsabit and also visited the coast dis- 

 tricts of Mazeras, Maji ya Chumvi, and the Taita Hills and 

 the inland districts in the Kakumega forest south of Mount 

 Elgon. Previously to these two journeys he accompanied 

 Carl Akeley to British East Africa in 1905, visiting the 

 highland region about the Athi Plains, Lake Naivasha, and 

 Molo on the summit of the Mau Escarpment, in addition to 

 the lowland districts near Voi. 



At present we know so little regarding the habits and 

 life-history of the various game animals that we find our- 

 selves at a loss to account for many of their most obvious 

 peculiarities. For instance, the distribution of almost any 

 game animal offers some features which with our present 

 knowledge are inexplicable. It is well known that every 

 animal, or plant for that matter, has strongly within it the 

 tendency to enlarge its distributional area until it covers 

 the habitable earth. It is equally well known, although 

 not so universally kept in mind, that the distribution of each 

 species marks the limits within which it is able successfully 

 to compete with its environment. It would appear, there- 

 fore, a comparatively easy matter to determine the factors 

 which are accountable for the distribution of any species; 

 and yet no task in natural history is more difficult. 



This is one of the fields open to sportsman and to 

 traveller alike. Dozens of factors enter into each case; and 



