266 ORIGIN OF SPECIES 



as possible ought to be given ; but want of space prevents me. 

 I can only assert that instincts certainly do vary — for in- 

 stance, the migratory instinct, both in extent and direction, 

 and in its total loss. So it is with the nests of birds, which 

 vary partly in dependence on the situations chosen, and on 

 the nature and temperature of the country inhabited, but 

 often from causes wholly unknown to us : Audubon has given 

 several remarkable cases of differences in the nests of the 

 same species in the northern and southern United States. 

 Why, it has been asked, if instinct be variable, has it not 

 granted to the bee "the ability to use some other material 

 when wax was deficient"? But what other natural material 

 could bees use? They will work, as I have seen, with wax 

 hardened with vermilion or softened with lard. Andrew 

 Knight observed that his bees, instead of laboriously collect- 

 ing propolis, used a cement of wax and turpentine, with 

 which he had covered decorticated trees. It has lately been 

 shown that bees, instead cf searching for pollen, will gladly 

 use a very different substance, namely oatmeal. Fear of any 

 particular enemy is certainly an instinctive quality, as may 

 be seen in nestling birds, though it is strengthened by experi- 

 ence, and by the sight of fear of the same enemy in other 

 animals. The fear of man is slowly acquired, as I have else- 

 where shown, by the various animals which inhabit desert 

 islands; and we see an instance of this even in England, in 

 the greater wildness of all our large birds in comparison with 

 our small birds ; for the large birds have been most persecuted 

 by man. We may safely attribute the greater wildness of our 

 large birds to this cause ; for in uninhabited islands large birds 

 are not more fearful than small ; and the magpie, so wary in 

 England, is tame in Norway, as is the hooded crow in Egypt. 

 That the mental qualities of animals of the same kind, born 

 in a state of nature, vary much, could be shown by many 

 facts. wSeveral cases could also be adduced of occasional and 

 strange habits in wild animals, which, if advantageous to the 

 species, might have given rise, through natural selection, to 

 new instincts. But I am well aware that these general state- 

 ments, without the facts in detail, will produce but a feeble 

 effect on the reader's mind. I can only repeat my assurance, 

 that I do not speak without good evidence. 



