IMITATION AND MIMICRY. 319 



most cases, be recognised as imitations. This re- 

 mark is confirmed by the fact, that mock- birds, 

 which may be considered as having 1 no natural song 

 of their own, cannot go through with any set of 

 notes, without introducing tones foreign to the notes 

 they are imitating. The mock-bird of this country" 

 (Ripcecola salicarid), " whose retired habits cause 

 it to be but little attended to, may be heard hurrying 

 over in succession the song of the wren, wagtail, 

 and sky-lark, the twitter of the swallow, and the 

 chirp of the sparrow and the chaffinch ; but it often 

 introduces a deep harsh note, which belongs to no 

 other native bird, though it has a distant resemblance 

 to the chirr of the white-throat. Indeed, the mock- 

 bird, both in its size and colour as well as in its 

 habits, is so like the white-throat as to be often con- 

 founded with it*." 



Now though we are willing to admit that there is 

 considerable plausibility in this view of the matter, 

 yet the circumstances appear susceptible of an ex- 

 planation more likely, we think, to be true. From 

 the sedge-bird frequenting the solitary banks of 

 weedy streams and ditches, it can have few oppor- 

 tunities of hearing the notes of the chimney-swallow, 

 and much less of the house-sparrow, even supposing 

 it disposed to learn them. And among some hun- 

 dreds of these birds which we have listened to in the 

 most varied situations in the three kingdoms, all 

 seemed to have very nearly the same notes, repeated 

 in the same orderf; a fact which appears to us to be 

 fatal to the inference of the notes being derived, not 

 from one, but a number of other birds. For if this 

 were so, it is not possible that these imitated notes 

 should all follow in exactly or very nearly the same 

 order in the song of each individual imitator in 

 different and distant parts of the country. 



* Edin. Mag,, Jan. 1819, p, 10, f J. R. 



