mth incidental Remarks. 345, 



at the commencement of this account ; which is analogous to 

 the clear and lively whistle with which the blackcap usually 

 concludes. This note is also sometimes repeated, as it flies, 

 in a vacillating manner, from tree to tree. 



In the young of this species the colour of the iris is very 

 dark, appearing at first sight black ; the following spring it 

 becomes hazel, with a tinge of reddish ; the next year it is 

 pale olive brown ; gradually becoming lighter and lighter, 

 till at length it is of the purest white. In this state I have 

 kept in confinement a fine male, and have since seen another 

 individual, a female, in which the irides were perfectly colour- 

 less. They are seldom thus met with, because so many years 

 must elapse before the colour entirely disappears ; and in all 

 birds there is always a great preponderance of young indi- 

 viduals. Montagu's description must have been taken from 

 one three years old ; as the irides are said to be " yellowish, 

 with a tinge of pearl colour." In the males of the common 

 whitethroat, the iris does not acquire its rich yellow until 

 the second or third year. [I have, this morning, shot one 

 with white irides. [Mr. Blyth, in a letter dated May 30.)] 



I hope this long digression will be pardoned. I have been 

 thus diffuse, because the lesser whitethroat seems but very 

 partially known, judging from most of the descriptions of it 

 which I have hitherto seen. Of these, that in Professor 

 Rennie's edition of Montagu's Dictionary is decidedly the 

 best, the editor being well acquainted with the bird. 



26th. Heard the sibilous petty chaps (or wood wren, Sylvia 

 sibilatrix) for the first time. 



30th. On this day I was informed, that, among the numer- 

 ous swifts playing around the Garrat copper mills, on the 

 Wandle, was one individual of a larger size, and rather 

 paler than the rest, with a white line along the belly. This 

 I immediately recognised to be Cypselus alpinus [described 

 in VI. 286, 287-], so took my gun, and went direct in 

 search of it ; but, ere I arrived at the place, all the swifts had 

 disappeared. 



May 3d. Did not hear the garden fauvette (Curriica 

 hortensis) until now. In an excursion, on May 8., over 

 Penge Woods, near Sydenham, I observed this species to 

 be more abundant than I had ever known it before. For 

 miles, the whole neighbourhood was vocal with their deep 

 and mellow warblings. They did not here become common 

 till about this time. Grey flycatchers were now plentiful. 



5lh. The common flusher (Collurio vulgaris) made its 

 appearance; and the turtle dove was first heard. A finished 

 dove's nest was found on the 18th. Though the turtle dove 



