FABLE AND FOLKLORE 79 



The danger of error in drawing inferences as to pur- 

 pose in nature is great in any case; but it is doubly so 

 when the philosopher is mistaken as to his supposed 

 facts. 



By going back a few decades one might find examples 

 of more or less amusing errors in natural history to the 

 point of weariness, but with one or two illustrations from 

 The Young Ladies' Book (Boston, 1836), I will bring 

 this chapter to its end. This little volume, doubtless Eng- 

 lish in origin, was intended for the entertaining instruc- 

 tion of school-girls, and in many respects was excellent, 

 but when it ventured on American ornithology it put 

 some amusing misinformation into its readers' minds. It 

 teaches them that our butcherbirds "bait thorns with 

 grasshoppers to decoy the lesser insectivorous birds into 

 situations where they may easily be seized" — a beautiful 

 sample of teleological assumption of motive based on the 

 fact that the shrike sometimes impales dead grasshoppers, 

 mice and so forth on thorns or fence-splinters, having 

 learned apparently that that is a good way to hold its 

 prey (its feet are weak, and unprovided with talons) 

 while it tears away mouthfuls of flesh. Often the victim 

 is left there, only partly eaten, or perhaps untorn; and 

 rarely, if ever, does the shrike return to it, and certainly 

 it attracts no "lesser insectivorous" birds nor any other 

 kind. 



The author also instructs his young ladies that "the 

 great American bittern has the property of emitting a 

 light from its breast," and so forth. His authority for 

 this long-persistent and picturesque untruth was a review 

 of Wilson's American Ornithology in Loudon's Magazine 

 of Natural History (London, Vol. vi., 835.) Speaking 

 of this familiar marsh-bird, which, let me repeat, has 



