8 ARKIV FÖR ZOOLOGI. BAND 2. N:0 15. 



a primitive characteristic, and at the same time this cha- 

 racteristic is connected witli a life in forests, as Lydekker^ 

 bas suggested. But then it is only a consequence that such 

 forms that leave the forests and Kve in a more open (and dry) 

 €Ountry may loose the stripes as a secondary adaptation to 

 the changed surroundings. The southern and eastern races, 

 without stripes, are thus representatives of a låter develop- 

 ment. As a rule, the female and young specimens have the 

 striped pattern better developed, as is to be expected when 

 it is an ancestral characteristic. But the female of T. s. 

 ornat US forms, cm^iously enough, an exception from this rule 

 having only half as many stripes as the male and less con- 

 spicuous too. In most species of Bushbucks the males are 

 black or blackish below, clarker than above, except partially 

 in bor and meneliki. The general colour of the males is also 

 darker or less red than in the females and youngs, but thivS 

 is only in accordance witli a general rule among the Rumi- 

 nants which have reddish or rust-coloured calfs even when 

 both parents are dark e. g. Anoa, Hippoiragus niger, Alces 

 etc. And in many others the young animals, and the females 

 are less dark than the adult males. The general darkening 

 of the adult males, that is the greater development of mela- 

 iiine pigment in them, I think, is to be regarded as a sign of 

 strength and virility, and a result of increased metabolism in 

 the same way as the males of many lower verta brates to- 

 wards and for the breeding-season assume a coat which is 

 more or less completely blackened by melanine-pigment-. 

 Instances of such a process are given by birds as well as by 

 fishes. The dark hue of the adult male Ruminants may be 

 interpreted as a parallel phenomenon to this which has be- 

 come perpetual. In some cases when both sexes were large 

 and strong, and carried weapons for defence, f. i. Buffaloes 

 and similar animals, this dark hue could, without danger, be 

 inherited by the females. In other cases, as in the Bush- 

 bucks, it was more suitable that the defenceless females re- 

 tained the reddish and paler hue which is less conspicuous, 



' »Mostly Mammals». London 1903. 



- Such a vjew is greatly confirnied by the fact told by Darwin 

 that, ii a young male Nilgai is emaseulated ]:)efoi'e it has obtained the 

 dark coat of the adult male. it never ohanges color. And the same autho- 

 vity States that the emasculated Banteng-bull »roverts to the color of the 

 female» (that is biown instead of black). 



