ORIGIN AND DEVELOPMENT OF INSTINCTS. 183 



low down in the psychological scale as the insects, we are not 

 without evidence of individual variations of instinct. Thus, 

 for instance, Forel observed great diversities of building 

 among the F. truncicola — the nests being sometimes domed, 

 sometimes made under stones, and sometimes excavated in 

 the wood of old trees. Likewise, Biichner observes, " one 

 ant will let herself be killed rather than let go the pupa 

 which she holds, while another will let them fall and run 

 away like a coward," and similar statements are made by 

 Moggridge. 



liut as showing strongly marked individual differences of 

 disposition in animals, and also that such differences may 

 h-ad to useless or capricious actions having all the strength 

 of incipient instincts, I think a good class of cases to select 

 are those in which one animal conceives a strong though 

 senseless attachment to another animal of a different species. 

 Thus, for instance, I once found a wounded fividgeon on the 

 shore, and took it home to my poultry yard. After a time 

 its wounds healed, and I then cut its wings to keep it as a 

 pet. The bird soon became perfectly tame, and then con- 

 ceived a strong, persistent, and unremitting attachment to a 

 peacock which also belonged to the establishment. "Wherever 

 the peacock went the widgeon followed like a shadow, so 

 that during the day time the one bird was never seen without 

 the other being in close attendance. If a separation were 

 forcibly effected, the distress of the widgeon was very great, 

 and she would whistle incessantly till restored to her old 

 place waddling behind the tail of the peacock. This devoted 

 attachment was the more remarkable from the fact that it 

 was not in the smallest degree reciprocated by the peacock. 

 lie never paid the slightest heed to his constant companion, 

 nor, indeed, did he seem to notice that she was always just 

 behind him. At night he used to roost upon the gable of a 

 cottage. The poor widgeon could not fly to accompany him, 

 ami even if she could would probably not have been able to 

 sit upon tin- gable; but she always kept as near him as cir- 

 cumstances would permit, for as soon as he Hew up to his 



gable she would squat herself down upon the ground just 



obaerred in the text, inch inat*n<w migbl be multiplied indefinitely j hut ns 

 h oonaidenble number of additional and well leleeted owee are given in 



Mr. Darwin it the end of this book, it is needleM fur mo to utKluco 



any further illustrations. 



