144 



ANIMAL LIFE IN DESERTS 



colour and distribution of these races finds its 

 parallel in the hares, Lepus pallidior, which is pale 

 and greyish and is found along the south side of 

 the Atlas Mountains, and L. whitakeri, which is 

 reddish sandy, and is found in the country round 

 Ghardaia. Meinertzhagen has studied certain races 

 of another species of Crested Lark {Galerida cristata) 

 and arranges them thus, beginning with the darkest 

 and ending with the palest. 



He quotes also the mean relative humidity and 

 the mean rainfall of the locaUties, both for the year, 

 and for the months April and May, when the birds 

 are breeding. He concludes that " Crested larks 

 are influenced in the colour of their plumage by 

 protective resemblance to the soil on which they 

 live, and that neither humidity nor rainfall has any 

 effect on their plumage. This same influence seems 

 to affect nearly all ground-birds which more or less 

 live in the open, such as Ammomanes, Alcemon^ 

 CEnanthe deserti, Eremophila, Alectoris, Pterocks, etc." 



