( 320 ) 



5. The Seuegambian Eland, Taurotragus derbianus. According to Mr. 

 Rothschild (op. cit.) there are no characters by which the head of the Sudan 

 eland can be distinguished from the typical T. derbianus of Senegauibia, and it 

 is therefore highly probable that both should be included nuder the present name. 

 The body of derbianus is characterised by the bright chestnut ground-colour of 

 the coat and the profuse white striping, the number of stripes being usually fourteen 

 or fifteen, so far as is known. Black knee-bands are present. 



So far as the races included under the specific title of T. oryx are concerned, 

 it will be clear from the above that there is complete gradation in the matter 

 of colouring from the Cape to the British East African animal — a gradation which 

 ought to be met with in all cases where we have to deal with races or subspecies, 

 although it has often been eliminated by differentiation. If, as suggested, 

 something approaching a similar gradation will eventually be found to connect 

 the British East African with the Sudan eland, it may be advisable to regard 

 T. derbianus merely as a race of the southern species, with the designation of 

 T. oryx derbianus. 



Whether or no snch a gradation, or partial gradation, really exists, it is quite 

 apparent that elands (which were probably once a northern type, since their 

 remains occur in the Pliocene of Southern Europe and India) show a modification 

 from a broad-eared, chestnut-coloured, forest-dwelling animal, profusely marked 

 on the body with white stripes, white streaks on the face, a black neck, and 

 black-gartered legs, to one in which the whole colour (with the exception of the 

 face) is pale tawny while the ears are narrow, this latter type being evidently 

 adapted to a semi- or complete desert existence. In the matter of gradation (with 

 one gap) from one type of colouring to another as we proceed from north to 

 south (irrespective of whether this gradation is or is not complete), elands present 

 us with a condition exactly paralleled by that which occurs respectively in the cases 

 of the giraffe and the bonte-qnagga. Three such parallel instances occurring in 

 the same country are assuredly sufficient to demonstrate that protection is the 

 main factor in the evolution of the colouring of great game animals. 



EXPLANATION OF PLATE. 



Head and neck of the type specimen of Taurotragus oryx patter 'sonianus, 

 from the Laikipia plateau, British East Africa, preserved in the British Museum 

 (Natural History). 



