Habit and Instinct. 



special and often very elaborate ways. One has only to 

 examine such a common nest as that of the chaffinch to 

 be profoundly impressed with the skill and, if one may so 

 put it, the delicacy of touch of which it affords such un- 

 mistakable evidence. The nests of the golden-crested 

 wren, the blue-tit, the sand-martin, the reed-warbler, 

 which is made so deep that the eggs do not roll out 

 though the supporting reeds be waved by the wind almost 

 to the surface of the water — each so different and yet each 

 in its way so admirable — tell the same tale ; as do such 

 foreign nests as those of the Baltimore oriole, a pensile 

 structure of grasses, bark, and various plant-fibres, firmly 

 and beautifully interwoven, or those of the tailor-bird, 

 daintily stitched with fibre, or hair, or bits of thread. If 

 further and fuller investigation and inquiry establish the 

 truly instinctive nature of nest-building, we must not 

 fail to realize the delicate complexity of the congenital 

 activities concerned. And then we must ask the question : — 

 Can all the niceties of the congenital process be attributed 

 to natural selection ? If not, Can it be regarded as evidence 

 of the inheritance of acquired habit ? I find it somewhat 

 difficult to picture to myself the eliminative steps by which 

 the definiteness of nest-building in any given species be- 

 came congenital under natural selection. But I find it 

 almost equally difficult to make clear to myself how the 

 uniformity of type could result from the inheritance of 

 intelligently acquired habit. Intelligence is so individual 

 a faculty, enabling the organism to adjust his life to his 

 own special surroundings, that it is difficult to see how, out 

 of the somewhat divergent individualism to which in- 

 telligence tends, there could come that stereotyped uni- 

 formity which the nests of any given species present- 

 Imitation would no doubt tend to uniformity, but here, 

 again, it is difficult to see why a bird should imitate the 



