VOYAGE UP WHITE NILE 
59 
sun. Among wildfowl, we here first come in contact 
with mobs of the white-faced tree-duck, miscalled 
throughout Africa (and India, too) the “whistling-teal”— 
for it is not a teal, though it does whistle!—and the 
comb-goose, of which two anon. 
Amidst such varied multitudes, many new to the eye 
of a British ornithologist, the singular divergence in 
design adopted by Nature in fashioning creatures clearly 
closely allied, and destined to seek their livelihood by 
practically identical methods, must compel attention. 
Thus—-to take a single example—the extreme difference 
Hagedash Ibis —Compare with 
figure of Glossy Ibis overleaf. 
A Spook-like Apparition. 
“ Openbill Over.” 
in general outline of the ibises is remarkable. There are 
four members of the genus, yet no two of them agree. 
The glossy ibis, long of leg, is trim and smart in build 
as a curlew; whereas his cousin the hagedash ibis 
displays such broadly rounded wings and tail—as it 
were like a crinoline 1 —as entirely to conceal the out¬ 
stretched legs when flying. The other pair of the 
quartette of ibises—though all live alike—are equally 
divergent from the two named. The comparative 
1 The only other bird, within my experience, in which this “crinoline” 
dress is so fully developed is a raven known as Corvus affinis , which we 
met with among the Red Sea hills (see sketch, p. 380.) It also, like the 
ibises, has a local analogue in the one other type of raven found in the 
same hills and living in the same way, Corvus umbrinus , which is entirely 
devoid of these extraordinary appendages. Perhaps the bush-larks (. Mirafra ) 
should also be cited. 
