INSTINCT. 295 



teaching or example ; whereas reason, without in- 

 struction, would often vary, and do that by many 

 methods which instinct effects by one alone. Now 

 this maxim must be taken in a qualified sense, 

 for there are instances in which instinct does vary 

 and conform to the circumstances of place and 

 convenience. 



It has been remarked, that every species of 

 bird has a mode of nidification peculiar to itself, 

 so that a schoolboy would at once pronounce on 

 the sort of nest before him. This is the case 

 among fields, and woods, and wilds ; but, in the 

 villages round London, where mosses and gossa- 

 mer and cotton from vegetables are hardly to 

 be found, the nest of the chaffinch has not that 

 elegant finished appearance, nor is it so beautifully 

 studded with lichens, as in a more rural district ; 

 and the wren is obliged to construct its house with 

 straws and dry grasses, which do not give it that 

 rotundity and compactness so remarkable in the 

 edifices of that little architect. Again, the regular 

 nest of the house-martin is hemispheric ; but where 

 a rafter, or a joist, or a cornice, may happen to 

 stand in the way, the nest is so contrived as to 

 conform to the obstruction, and becomes flat, or 

 oval, or compressed. 



In the following instances, instinct is perfectly 

 uniform and consistent. There are three creatures, 

 the squirrel, the field-mouse, and the bird called 

 the nut-hatch, (sitta Europced) which live much 

 on hazel-nuts, and yet they open them each in 

 a different way. The first, after rasping off the 

 small end, splits the shell into two with his long 

 fore teeth, as a man does with his knife ; the second 

 nibbles a hole with his teeth, so regular as if 

 drilled with a wimble, and yet so small that one 

 would wonder how the kernel can be extracted 



