INTRODUCTORY 
9 
within half-gunshot; in proof whereof I have sketched all 
these and even the roan (shockingly badly, it is true), 
close at hand, yet wholly unconscious of my presence. 
New countries present new sensations. The hunter at 
first is beset with surprises. Much of the big-game of 
Sudan is associated in his mind with the co-existence of 
several other kindred species; but here the latter are 
lacking. In vain his eye scans Nilotic plain for the 
shaggy figure of the brindled gnu, or for its customary pal 
the zebra. Why are they absent? Again, in these 
forests of Sudan he might reasonably expect to find the 
noble sable, with impala on their outskirts. But no ; for 
some inscrutable reason the four familiar friends just 
named all elect to stop short, somewhere down by the 
Equator. The Sudan they utterly eschew, though its 
forests and veld appear precisely adapted to their require¬ 
ments, and just such country as they love further south. 
Geographical distribution presents a series of enigmas, 
and the principles that govern it are steeped in mystery. 
Certain animal-forms persist practically throughout the 
length of Africa. Others, though of precisely similar 
tastes, arbitrarily limit their range within rigid bounds, 
though neither palpable cause nor physical barrier exists. 
In those regions where the range of the two groups 
coincide, both sets live alongside and even herd together. 
Obviously they are not antagonistic, socially or economic¬ 
ally. Their habits and requirements agree. Why do 
their ranges differ? The total absence from the Sudan of 
several species which logically ought to inhabit it is 
striking—almost speechful. Witness the four cited-—the 
gnu, impala, sable, and zebra; and many more might be 
mentioned. 
A majority of the African game-animals (especially the 
antelopes) unquestionably affect the Southern Hemisphere 
and presumably sprang therefrom, though many have 
extended their range northwards till stopped in mid- 
Sudan by the barrier of Sahara. On the other hand, 
