220 NATURAL HISTORY 



latter be much of a songster ; but in this 

 matter I want to be better informed. The 

 former has a variety of hurrying notes, and 

 sings all night. Some part of the song of 

 the former, I suspect is attributed to the 

 latter. We have plenty of the soft-billed 

 sort ; which Mr. Pennanl had entirely left 

 out of his British Zoology, till I reminded 

 him of his omission. See British Zoology 

 last published, p. 16.* 



■ I have somewhat to advance on the dif- 

 ferent manners in which different birds fly 

 and walk ; but as this is a subject that I 

 have not enough considered, and is of such 

 a nature as not to be contained in a small 

 space, I shall say nothing further about it 

 at present. t 



No doubt the reason why the sex of birds 

 iu their first plumage is so difficult to be 

 distinguished is, as you say, ** because they 

 " are not to pair and discharge their pa- 

 " rental functions till the ensuing Spring." 

 As colours seem to be the chief external 



• See letter xxv. to Mr. Pcunintt. 

 f Sec letter xlii. to Mr. Barringfon. 



