246 INSTINCT. 



prevents me. I can only assert that instincts certainly do 

 Yary — for instance, 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 south- 

 ern 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 soft- 

 ened with lard. Andrew Knight observed that his bees, 

 instead of laboriously collecting propolis, used a cement of 

 wax and turpentine, with which he had covered decor- 

 ticated trees. It has lately been shown that bees, instead 

 of 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 nest- 

 ling birds, though it is strengthened by experience, and by 

 the sight of fear of the same enemy in other animals. The 

 fear of man is slowly acquired, as I have elsewhere shown, 

 by the various animals which inhabit desert islands; and 

 we see an instance of this even in England, in the greatci' 

 wilduess 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 

 wai-y 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. Several cases could also be adduced of occa- 

 sional and strange habits in wild animals, which, if advan- 

 tageous to the species, might have given rise, through 

 natural selection, to new instincts. But I ani well aware 

 that these general statements, 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. 



