APPENDICES 417 



500 yards the conspicuous stripes of the zebra become in- 

 distinguishable, or " melt into monotone." Quite poetic ; though 

 in plain prose I prefer to explain the phenomenon by the simple 

 fact that human eyesight at such distances ceases to recognise 

 minor detail. But by what process of mental athletics can that 

 everyday fact be construed into evidence that thereby the 

 zebra is rendered less visible? 



Consider how such phantasies work out on the open veld. 

 There, in full view, stands your zebra more probably twenty, 

 forty, or a hundred zebras, covering acres of ground striped 

 or "melted monotone" according to distance. The colour 

 matters not a whit ; the animals are, of course, as easy to see at 

 500 yards or at 5000 as are cattle or ponies on an open down 

 at home. For zebras are big upstanding beasts, over 13 hands 

 high and bulky of build, conspicuous to the most moderate 

 eyesight. Moreover, they are not all " melted monotone," 

 even at the 5OO-yard range. Only those that happen to be 

 facing the light, while full broadside to the observer, could be 

 described so; those which stand broadside-on to the light 

 show up silvery-white; others posed athwart the light appear 

 coal-black ! No two necessarily agree suum cuique colorem, 

 varying with the angle and impact of the light. But let 

 their colour be what it may, none can fail to see them, save 

 the blind. See sketch at p 437. 



Will any theorist dare contend that in an English landscape 

 cattle or sheep are " colour-protected " ? No : because such a 

 proposition would conflict with common knowledge and with 

 common-sense alike. But the case of the zebra on African 

 veld differs in no way whatever nor does that of any large 

 animal (beast or bird) in full view, far or near, so it be within 

 the range of vision. 



Zebra, moreover, are not the sole denizens of the open 

 plain. That group to the right or left, it matters not are 

 hartebeests, red as foxes ; and nearer the fringing forest graze 

 a dozen impala, redder still ; while beyond stands a column of 

 brindled gnus, these last of a clear slate-blue, which in African 

 sunlight stand out conspicuous as a string of marble statues 

 at a couple of miles. Each of the four species display totally 

 different colours and all clearly distinguishable by eyesight. 



2 D 



