546 MOTACILLID^. 



South Downs and the sea ; but as they advance towards 

 Brighton the migrating bands, consisting chiefly of the young 

 of the year, accumulate in vast flocks, and thus they seek the 

 adjoining county of Kent, whence the voyage to the continent 

 may be performed with ease and security even by birds but 

 a few months okl and unequal to protracted flights.* 



The adult male in the breeding-plumage, which begins to 

 appear in March and is completed in April, has the bill and 

 irides almost black : the front and sides of the head white, 

 extending over the eyes, and forming a patch on the sides of 

 the neck ; the crown and back of the head, the nape, back, 

 scapulars, rump and upper tail-coverts, black ; the small and 

 great wing-coverts black, broadly edged and tipped with 

 white ; the primaries and secondaries black, with narrow 

 lighter-coloured outer edges ; the third, fourth and fifth 

 primaries, with some white on the inner web ; the tertials 

 black, with broad white outer borders ; the eight middle 

 tail-feathers black ; the two outer tail-feathers, on each side, 

 white, with a black edge on the inner web ; chin and throat 

 black, wliicb, passing upwards behind the white patch on the 

 sides of the neck, unites with the black of the scapulars and 

 nape ; breast, belly and lower tail-coverts white ; sides of the 

 body and flanks black : legs, toes and claws black. 



The whole length of the male is seven inches and a half; 

 from the carpal joint to the end of the wing, three inches 

 and three-eighths. 



The adult female is half an inch shorter in the whole 

 length than the male, but otherwise differs only from him, 

 at this season, in having the back lead-grey, mottled with 

 darker feathers. 



In the adult of both sexes in winter, the black of the head 

 and nape of the neck does not extend to the back, which 

 is then nearly uniform ash-grey ; chin and throat white ; 



* The abstract above given of Mr. Knox's remarks (originally printed in the 

 ' Zoologist ' for 1843 and subsequently revised for his ' Ornithological Rambles ') 

 not only proves him to be a master of the observed facts relating to migration, 

 but also, unless the Editor is mistaken, the first English ornithologist who pointed 

 out the essential diiference of the mode of emigration and immigration. 



