58 BIRDS OF THE COUNTRYSIDE 



mottled with spots of blood-purple — an architectural 

 masterpiece woven of moss, strengthened with small 

 twigs, dried grasses and wool and sprinlded with lichen, 

 the lining being made of feathers, vegetable down, and 

 horsehair. It was fixed to a horizontal branch three 

 feet from the ground and at least two from the body 

 of the hedge, so that it was clearly visible some distance 

 away. In the long grass at the foot of the same hedge 

 thirty yards away there was an ingeniously concealed 

 chiff-chaff's nest, which I should never have discovered 

 but for flushing the sitting-bird, which perched near 

 by, wailing the anxious hui, hweet. When I was parting 

 the grass I made a clumsy movement, and to my 

 regret disarranged the upper part of the dome. I retired, 

 thinking it would be better to leave repairs to the builder 

 — ne sutor ultra crepidam — and hoping all would be well. 

 I returned an hour later, and found that she had perfectly 

 re-thatched the roof of her hamlet. 



Blackbird, chaffinch and chiff-chaff taught me a 

 good deal that day. When a rook drops a mussel on 

 the rocks, it is acting intelligently, perceptually, with 

 a definite and conscious end in view.^ When a bird 

 builds a nest, it is acting instinctively, upon " uncon- 

 scious memory," and spending its ancestral gains. The 

 end is perfectly, but not (so far as we know) consciously 

 achieved. The bird is obedient to a passionate germinal 

 impulse. But the choice of nesting sites brings individual 

 as opposed to racial, and intelligent as opposed to 

 instinctive faculties into play. Complexity both of 

 conditions and of needs, a nexus of problems, fluctuating 

 from year to year, confront each separate pair of birds, 

 to be met and solved only by intelligence, or at any 

 rate, intelligence working upon a ground-plan of 

 instinct.2 There can be little doubt that Bergson was 



1 In fact, the only difference between the rook's and man's noblest 

 behaviour is that the one has a concrete, the other an abstract 

 end in view. 



* In Sussex this year, for instance, the trees on which a 

 rookery was situated were cut down, and the birds promptly 

 built their nests and raised their yoimg in rabbit holes. Sir F. C. 

 Gould told me of a nightjar which hatched two young among 

 the shingle on the Devonshire coast, the protective resemblance 



