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. galhula. I have known this to be the case 
with many birds, the Laniida 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 
