90 Mr. D. A. Bannerman on rare Birds [Ibis, 
juvenile and immature plumage, besides a number sent to 
me by Dr. van Someren. 
1 . The first plumage of C. solitarius lias the upper parts 
black (as in C. gabonensis ), but each feather of the 
head, mantle, back, rump, and wing-coverts is narrowly 
fringed with white or huffish-white, most pronounced 
on the head and nape. There is a conspicuous white 
spot at the base of the head. The throat and chin 
are black, each feather narrowly margined with white; 
the breast and belly buff, strongly barred with black. 
2. In the second stage the white margins to the feathers 
are less conspicuous; the breast and belly are white 
strongly barred with black, the under tail-coverts are 
white barred with black. On the upper surface the 
white spot at the base of the head is wider and more 
conspicuous, the rectrices are black, and the four 
white spots on the webs of the rectrices (including 
the central pair) have made their appearance—the 
latter an important character, as C. solitarius is the 
only Cuckoo of this complex group which has white 
markings on the webs of the central pair of tail- 
feathers. The white spot at the base of the head 
disappears entirely before the feathers of the upper 
parts lose their white edges. 
3. Stage number three is very similar to the last, but the 
chestnut feathers of the throat are beginning to make 
their appearance, and the underparts are rather more 
buff and are more conspicuously barred. The head 
and rest of the upper parts are uniform, the white 
margins to the feathers having entirely disappeared. 
4. The fourth stage shows the grey feathers of the throat 
appearing above the chestnut of the breast ; the 
under tail-coverts are now distinctly buff', with a few 
indistinct bars. 
5. In the fifth stage we see the adult bird with uniform dark 
grey upper parts, the conspicuous white markings on 
the webs of the rectrices including the middle pair ; 
