378 
SAVAGE SUDAN 
but obviously there exists no certainty whatever, far less 
proof. At best, such method is but an approximation 
to correctness; and “approximation,” as I have already 
defined it, is not strictly science, but speculation. Dried 
skins alone—each rigid as an old boot—afford no suffi¬ 
cient criterion. In my humble view, until the eagles— 
or vultures—or any other group whatever—have been 
closely studied in life by competent field-naturalist, any 
hard-and-fast definition of their status is not only pre¬ 
mature but mischievous. 
Eagles, of course—equally with my other favourites, 
the wildfowl—ever present the most strenuous opposition 
to being systematically “studied in life.” That, however, 
is no sort of excuse for trespassing beyond the bounds 
of ascertained facts; and, until their life-histories have 
been so investigated, I question the value of antecedent 
classification. Much water will flow down Nile ere we 
shall be able specifically to diagnose these Sudan eagles, 
and many other difficult genera, whether in the Sudan or 
elsewhere. 
Another magnificent Raptorial whose existence we 
had hardly suspected in the Sudan—the lammergeyer— 
came gliding along below the crests of these hills, always 
holding a course parallel with their contour, and never 
an effort of those mighty wings to be detected from the 
bird’s first appearance a mile ahead till it vanished behind 
some distant shoulder far behind—truly a striking object- 
lesson in the powers of aviation. The laws of gravity 
do not count. 
By ill-chance the lammergeyer never passed within 
range of our prepared posts ; and such opportunities as it 
did vouchsafe caught the hapless hunter unawares and 
totally unarmed for such heavy game—for to tackle the 
great bearded apparition with a *410 would be the 
equivalent of a torpedo-boat challenging a super¬ 
dreadnought. Though failing to bring home a specimen, 
we had opportunity to notice that its underside was 
