Albinos 



the Australian carnivorous marsupials, known 

 as Native Cats (Dasyurus). 



In domestic animals we frequently find the 

 following localisation of white white socks, 

 collar, breast, and muzzle. The arrangement 

 occurs in cats, dogs, rabbits, guinea-pigs and 

 mice, also in the horse and pig, but without 

 the collar. The arrangement is not seen in 

 goats, cattle, or sheep, nor in wild animals of 

 any kind. This would lead to the conclusion 

 that the combination is correlated with some 

 character unfavourable to survival under natural 

 conditions. 



Many variations which frequently occur among 

 both wild and domestic animals do not persist in 

 nature. 



As instances of such variations we may men- 

 tion pure albino forms, that is to say those in 

 which pigment does not occur in the eyes. 



It is easy to see why this variation is not 

 allowed to persist in nature. Its possessors are 

 handicapped by bad eyesight, and so have no 

 chance of surviving in the struggle for existence. 

 It is thus that natural selection acts. On the 

 other hand, white species with pigmented eyes are 

 fairly numerous. These enjoy normal eyesight, 

 but labour under the disadvantage of being easily 

 seen by their foes. Hence we find that white 

 species generally either occur in a snowy habitat, 

 or are powerful and both able and ready to 



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