Instinct and its Lessons 123 



lichen so as to resemble tree bark. The Gold-crest 

 hangs his nest, of moss lichen and wool, from the boughs 

 of a fir-tree, in such a manner as to be partially sus- 

 pended from one and supported by another. The 

 Chaffinch uses spiders' webs to produce what Waterton 

 calls his paragon of perfection. The Thrush manu- 

 factures a varnish of mud or cow-dung and rotten wood, 

 wherewith to line his nest, and the arboreal Nuthatch 

 plasters up the approach to his, except one opening, 

 very neatly, with clay. In the choice of materials, too, 

 birds will exhibit a power of discrimination which man 

 could rival only by a laborious process. Martins, for 

 example, seeking clay for their nests, will unanimously 

 select one puddle out of fifty equally convenient, their 

 diagnosis of the quality of its contents being seemingly 

 instantaneous, while we, to come to a sound conclusion, 

 should have to institute a long and tedious comparison. 



As to song, Mr. Wallace tells us that Linnets, edu- 

 cated in captivity under Larks, and Goldfinches under 

 Wrens, learn the notes of their instructors instead of 

 their own. But captivity, as is well known, alters habits 

 in an extraordinary degree ; though even in captivity a 

 young Skylark, without any instruction at all, will ac- 

 quire his native song. But in a wild state, is it probable 

 that Waterton's young Jackdaws learnt to chatter like 

 Magpies, or his Magpies to yelp like Jackdaws ? If we 

 were, on a large scale, to interchange the eggs of Black- 

 birds and Thrushes, or of Nightingales and White-throats, 

 should we expect any notable results to be apparent in 

 the minstrelsy of the district? One argument to the 

 contrary nature has exhibited in the Cuckoo, which 

 reared in the society of strangers, and with their notes 

 in his ear, yet sticks unfalteringly to the tune, which 

 only by instinct can he recognize for his own. Again, 

 how should a young bird learn from its parents the art 

 of mocking whatever sounds it hears? Our common 

 Sedge Warbler, for instance, will not only mimic the 

 Sparrows, Chaffinches, and Blackbirds around it, but 

 should it chance to hear the peculiar cry of a Guinea- 



