Birds. 



8759 



not stopping even while the little fellow drew between his mandibles 

 the feathers that form its eoverts. The only moment of cessation I 

 observed was when the bird stretched its wing and leg. It used to 

 engage itself in catching the flies among a pile of stones, perching on 

 the top, stamping its little feet, shaking its tail, and constantly turning 

 round and round in the same place. 



78. Budytes flava, L., var. Rayi. Our South China form of yellow 

 wagtail is the true Motacilla flava, L., having in full dress a gray head, 

 and white chin and eyebrow. From North China (Tientsin) I have 

 seen specimens not to be distinguished from the European B. cinereo- 

 capilla, with the entire head dark gray. In the island of Formosa the 

 Budytes has the head uniform in colour with the back, and a yellow 

 eyestreak in the adult plumage, being (except perhaps in the rather 

 darker ear-coverts) barely distinguishable from the form peculiar to 

 the British Islands. Indeed, so similar are the birds from these two 

 widely separated localities, that I can scarcely do otherwise than 

 regard them merely as varieties of the B. flava, their aberrancy from 

 the typical colour and their cosimilarity being due to some insular 

 and climatal causes which we cannot just now, with any certainty, 

 fathom. The peculiar greenness of the head is constant in all my 

 adult specimens, with one or two exceptions, which have more or less 

 gray on the forehead, and an inclination of the eyebrow and chin to 

 be white instead of yellow. This would doubtless likewise be found 

 if a large series of British skins were examined. This apparent 



? desire of nature to revert to the typical colour, and the absolute iden- 

 tity of the two forms in immature and undress plumage, resolve me in 

 setting down the Formosan as a variety ; for if we are to regard spe- 

 cies as special creations, how can we reconcile the fact of two islands, 

 separated by an entire hemisphere, producing the same form almost 

 entirely restricted to themselves, and represented on their opposite 

 mains and throughout the intervening vast tract of land by a single 

 species, of which specimens procured from the extreme east and 

 extreme west are positively identical ? The yellow wagtail is with us, 

 in Formosa, a constant resident, assembling in winter in large parties 

 and remaining about the fields. In spring it pairs, and scatters itself 

 about the country, resorting chiefly to the hill-side streams for the 

 purposes of nidification. I suspect also that a good many repair to 

 Japan for the summer. 



79. Anthus agilis, Sykes. 



80. A. cervinus, Pall. 



