COLOURS OF ANIMALS 



and the West Indies, and, among butterflies, in the smaller 

 Moluccas, the Andamans, and Madagascar, we cannot avoid 

 the conclusion that in these insular localities some general 

 cause is at work. 



There are other cases, however, in which local influences 

 seem to favour the production or preservation of intense 

 crimson or a very dark coloration. Thus in the Moluccas 

 and New Guinea alone we have bright red parrots belonging 

 to two distinct families, 1 and which therefore most probably 

 have been independently produced or preserved by some 

 common cause. Here, too, and in Australia we have black 

 parrots and pigeons ; 2 and it is a most curious and suggestive 

 fact that in another insular sub-region that of Madagascar 

 and the Mascarene islands these same colours reappear in 

 the same two groups. 3 



Sense-perception influenced by Colour of the Integuments 

 Some very curious physiological facts bearing upon the 

 presence or absence of white colours in the higher animals 

 have lately been adduced by Dr. Ogle. 4 It has been found 

 that a coloured or dark pigment in the olfactory region of 

 the nostrils is essential to perfect smell, and this pigment is 

 rarely deficient except when the whole animal is pure white. 

 In these cases the creature is almost without smell or taste. 

 This, Dr. Ogle believes, explains the curious case of the pigs 

 in Virginia adduced by Mr. Darwin, white pigs being killed 

 by a poisonous root which does not affect black pigs. Mr. 

 Darwin imputed this to a constitutional difference accompany- 

 ing the dark colour, which rendered what was poisonous to 

 the white-coloured animals quite innocuous to the black. Dr. 

 Ogle, however, observes that there is no proof that the black 

 pigs eat the root, and he believes the more probable explana- 

 tion to be that it is distasteful to them ; while the white pigs, 

 being deficient in smell and taste, eat it and are killed. 

 Analogous facts occur in several distinct families. White 

 sheep are killed in the Tarentino by eating Hypericum cris- 



1 Lorius, Eos (Trichoglossidae), Eclectus (Palaeornithidae). 

 2 Microglossus, Calyptorhynchus, Turacsena. 



8 Coracopsis, Alectraenas. 

 * Medico-Chirurgical Transactions, vol. liii. (1870). 



