166 
ALGERIA 
My scientific Bedawin pointed out to me the tracks on the sand 
of the Hare, the Jackal, the Jerboa, and the fine Indian Houbara 
Bustard 1 {Otis macqueeni , E. Gray). But it was much easier to track 
smaller game, such as the Pimelia and other beetles, (?) Agrotis larvae, 
and above all Lizards. The latter usually let their tails drag along the 
ground leaving a continuous line on the sand between the footprints, 
but when alarmed the creatures raise their tails aloft, seeming 
thereby to get greater freedom of movement. Thus a lizard trail 
consisting of foot-marks only is clear proof of “ full speed ahead,” 
which in the case of a desert lizard means a very notable pace. I 
have spoken previously of the rapid gait of Adesmia, Graphiqrterus 
and Anthia. In marked contrast to these are the heavy movements 
of Pimelia and Erodius , though they are very conspicuous. The big 
black Pimelias are often found with dents on their elytra; do these 
indicate attacks by birds ? That they are somewhat protected is 
suggested as well by their habits as by the fact that dead specimens, 
entire, but cleaned out by ants, are frequently met with; such are 
usually of a brown tint. The beetles of the genera Pachychila and 
Cleonus must be well protected by their hard integuments, but the 
latter are in addition cryptically coloured. 
Dr. G. R. Crotch’s opinion that the large wingless Heteromera so 
abundant in the Canary Islands are actually protected by their 
inability to fly has been already mentioned. 2 Here I found allied 
beetles very numerous on the outskirts of the Sahara. Could a like 
line of argument be reasonably followed here ? Could it be main¬ 
tained that if endowed with wings these beetles would have run 
serious risks of being lost in the desert ? I should be sorry to have 
to maintain that view. It would, however, seem to be a fact that 
the loss of wings by restricting locomotion has favoured the develop¬ 
ment of a great number of closely allied species inhabiting very 
restricted localities. 
But Beetles are not the only swift-footed desert insects; the 
Ant Myrmecocystus hombycimcs is remarkably quick in its movements, 
even for an ant. Indeed the state of habitual terror in which the 
denizens of the desert seem to live, sometimes quite “got on my 
nerves,” as the saying is. 
Among Birds the Desert Wheatear— Saxieola deserti, Temm., 
is a well-known instance of cryptic coloration. Seen from the side, 
as when, sitting on the ground, one looks at the bird perched on a 
1 By the kindness of Mr. R. T. Ussher I was enabled to try my first experiment in 
bird-skinning on a specimen of this bird. 
2 See above, p. 26. 
