18 INTRODUCTION. 



in holes and fissures, while in the Bureja mountains it seeks 

 hollow trees and avoids rocky crevices. So also with rab- 

 bits, which for several generations have lived where they 

 could not burrow ; the descendants of these non-digging 

 rabbits have lost the love or desire, formerly so strong in 

 them, of digging holes (Reclam). Darwin notes that the 

 Egyptian pigeons have changed, owing to the constant 

 neighborhood of the river, and have learnt to sit on the 

 surface of the Nile and drink from it like water birds. The 

 wolf, as Noll points out, is, in places where he is supreme, a 

 bold impudent robber, whereas he becomes a timid beggar 

 when he approaches cultivated places. The blackbird, 

 Turdus merula, was formerly a very shy bird, but in gardens 

 and in the suburbs of towns wherein it is spared and wel- 

 comed, it has become so confident that it builds its nest with 

 the help of bits of paper amid foliage where it is daily visited 

 by man, and takes its food from the windowsill in company 

 with sparrows. The ringdove, Columba palumbus, another 

 formerly shy bird, in Pfannenschmied, in East Friesland 

 (" Monthly Journal of the Saxon-Thuringian Society for 

 the Study and Protection of Birds," March, 1876), where a 

 suitable breeding place was wanting, nested in the direct 

 neighborhood of human abodes, and even in the most fre- 

 quented streets of the town. Dr. G. Jiiger ("In the matter 

 of Darwin against Wigand," p. 240) relates that he observed 

 a six-weeks old kitten, which possessed to so high a degree the 

 utterly uncatlike love of the bath, that he found it one 

 morning in his pan, and that no water vessel was safe from 

 it. The same observer noticed that each year a number of 

 young ones appeared among his oak- caterpillars, which 

 entirely lacked one of the most powerful instincts, that of 

 eating ; they would wander about restlessly over the food, 

 until they finally starved to death. In like manner we 

 often find suckling animals which lack the instinct of 

 sucking, and calves, which are generally taken away after 

 birth from the milch-cows, gradually forget how to suck. 



The silver sea-gull, Larus argentatus, according to Audu- 

 bon, sometimes, against its instinct, nests on trees, and cer- 

 tainly the older birds do this on White Head Island and the 

 neighboring islands ; they formerly nested in the swamps, 

 and they must have changed after they found out that their 

 eggs were annually taken from them by the fishermen; 



