BLUE NILE AND DINDER RIVER 
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you watch ; there are eagles too, also goshawks in two 
sizes, and fierce harriers, together with the small fry 
of the fleet—“destroyers”—such as the dashing merlin 
(Falco ruficollis ), kestrels of sorts, and manifold forms 
of death, each with piercing eye, a lightning speed, and 
ready talon. 
Beneath, in the depths of the pool, lurk hungry 
“water-wolves” ( Hydrocyon ), along with shoals of other 
voracious fish-—not to mention crocodiles—each ready 
to engulf any and every living creature that ventures 
within their reach ; or—as oft haps — is forced down 
in panic upon the deceptive surface. This explains why 
the martins and the bejewelled bee-eaters (though ever 
busy insect - hawking over the pools) are careful to 
preserve a margin of safety; yet even so, Mr Butler 
records having seen bee-eaters fall victims to a flying 
leap from under water {Ibis, 1905, p. 349). 
Such scenes of ordered violence and bloodshed— 
striking to us denizens of tamer lands where the full 
barbarity of the prime has almost ceased to obtrude— 
represent, nevertheless, nothing more than Nature’s 
schemes for the survival of the fittest, the struggle for 
existence, etc., in full view and actual operation. Anarchy, 
or the tyranny of the strong, are perhaps the best 
definitions. 
In these respects Nature’s methods run in the main 
on rough and ready-—not to say barbarous—lines ; but 
curious discrepancies appear. Thus a troop of grivet 
monkeys, emerging from the bush-clad bank opposite, 
cross the glowing sand ; they move with mincing step, 
and every few yards a sentry will stand bolt upright 
to reconnoitre. Yet almost overhead, conspicuously 
posted on a tall tamarind-tree, sits a great white-headed 
eagle. Him the monkeys utterly ignore; and the neglect 
is reciprocal. Why does the eagle refuse so soft a 
chance ? One can only assume that, unlike the Arabs, he 
is not Pithecophagous, and, moreover, that the monkeys 
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