II RECOGNITION MARKS 35 



species at a distance, for it would be equally 

 recognisable by all predatory animals, and caribou 

 and white-tailed deer or African antelopes cannot 

 escape from wolves or wild dogs by running like 

 rabbits into burrows. 



Personally, I cannot ser why large antelopes 

 which live in herds on open plains should require 

 special recognition marks, as in such localities the 

 bulk of an animals whole body would be plainly 

 visible at a great distance no matter what its colour 

 might be. If an antelope became separated from 

 its fellows by night, all so-called recognition marks 

 would be invisible at a very short distance. It 

 must be remembered, however, that every species 

 of animal has a peculiar and very distinctive smell 

 of its own, and my own observations would lead 

 me to believe that most wild animals recognise 

 one another, as a rule, more by scent than by sight. 



It seems difficult to believe that there can be 

 any truth in the theory suggested by Mr. Wallace, 

 that recognition marks have been developed in 

 certain species of large mammals because they are 

 necessary to enable nearly allied species of animals 

 to know their own kind at a glance, and so prevent 

 interbreeding ; for the ranges of very nearly allied 

 forms of one genus, such as the various species of 

 hartebeests and oryxes, or the bontebok and the 

 blesbok, very seldom overlap, and so each species 

 keeps true of necessity and without the help of 

 special recognition marks. Where the ranges of 

 two nearly allied species do overlap interbreeding 

 probably will take place. 



There seems little doubt that the species of 

 hartebeest known as Neumann's hartebeest has 

 interbred with Jackson's hartebeest in certain dis- 

 tricts where the ranges of the two species meet. 

 In the neighbourhood of Lake Nakuru, in British 

 East Africa, I shot, in February 1903, a hartebeest 



