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 A SPOOK-LIKE APPARITION. 



figure of Glossy Ibis overleaf. "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 riven 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 (Mtrafra) 

 should also be cited. 



