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SAVAGE SUDAN 
rat-snakes. [Note that, in my bedroom at Khartoum, I 
had caught a similar snake (scientific name, Zamenis ), a 
fortnight before.] A third carried a striped rat in his 
talons, and Mr Butler records seeing one tackle a six- 
foot cobra. 
This goshawk is designed in two sizes—or it would be 
more scientific to say that Nature has duplicated it in a 
second type of half its bulk. The latter is distinguished 
as Melierax gabar and—curiouser and curiouser—this 
latter has a double form, the majority being ash-grey like 
their bigger relative, while a minor proportion are entirely 
black. We shot several of both sizes and the smaller in 
the varying colours specified, both on the White and Blue 
Niles; but that the phenomenon is merely a colour- 
dimorphism (such as occurs with the Arctic skua, 
Sabine’s snipe, reef-herons, etc.,) is demonstrated by the 
fact that unfledged young in the same nest exhibit an 
exactly similar variation.— Teste , Sir Geoffrey Archer. 
THE TWO JEBELS OF WHITE NILE 
On all its 627-mile course, White Nile boasts but two 
upstanding hills—and they are little better than koppies—- 
Jebelein and Jebel Ahmed Agha, distant 239 and 340 miles 
from Khartoum respectively. The latter, though it stands 
in the best of the big-game country, needs no words. 
An isolated pyramid of black disintegrated shale, 350 feet 
high, it is largely occupied by bees (which resent human 
intrusion), and by little else of interest to a naturalist. 
Jebelein, on the contrary, proved a regular stronghold 
both of wild beasts and of interesting birds. It comprises 
a group of conical granite piles, 500 feet high, and cover¬ 
ing miles of space. I remember my first evening there. 
We had been required to bring home local examples of the 
hyrax. It was nearly dusk when, having bagged a brace 
or two of those beasties, a keen-eyed Arab lad, Achmet 
by name, who had attached himself to me, eagerly pointed 
to a crevice in the crags some 30 yards above. Quite 
