292 Mr. R. Swinhoe on Formosan Ornithology. 



the tip and ciliated. Eye-rim dark yellowish brown. Iris 

 greyish brown. Legs rich leaden violet, with pale yellowish 

 sole-pads, and light edges to scutes ; claws black, with pale edges. 

 The immature bird is strongly tinged with olive-green on the 

 upper parts, the crown being yellower, and the quills of a lighter 

 black. The two central tail-feathers are greenish yellow, and 

 the dark parts of the rest more or less impregnated with that 

 colour. The throat, breast, and belly whitish, marked with long 

 black streaks, very faint on the first of the three. When the 

 birds return in the spring, the plumage has undergone a decided 

 change. The bill has become pinkish, still marked a little with 

 brown ; the black nape-band has appeared. The yellow of the 

 upper parts and wings is still strongly tinged with olive-green ; 

 but the dark parts of the tail-feathers and the two central ones are 

 almost entirely blackened. The under-parts have become bright 

 yellow ; but the streaks still continue, though fainter. In the 

 next moult the streaks disappear ; the black and yellow parts 

 become brighter; but the back is still tinged with green. 

 On the second spring-return all the light parts have become a 

 fine golden yellow, except the tips of the primaries, which are 

 whitish ; and the black has intensified to a glossy hue. The bill 

 has become a fine clear pink, the legs a fine dark slate-colour, 

 and the iris a speckled purplish brown. When quite mature, 

 the males and females are similar, but the adult plumage of the 

 male is more quickly developed than that of the female ; and 

 hence, though you very frequently see a green and spotted female 

 paired with a yellow male, and breeding, it is only males of late 

 broods of the previous year that are seen breeding in imma- 

 ture plumage. This is consequently a much rarer sight ; but it 

 does occur. I have dissected birds in full plumage, and found 

 them to be females. Mr. Blyth tells me that he has observed 

 the same facts with regard to the Indian Orioles; and Prof. 

 Schlegel has lately assured me that the same holds good with the 

 European bird, O. galbula. I have known this to be the case 

 with many birds, the Laniidce for example. The male in mature 

 and the female in immature plumage are usually found together ; 

 but later investigations have proved that in course of time the 

 female acquires the same plumage as her lord — for some reason 



