Its track corresponded well with the description of the reptile given me by my men, for, outside the marks where its feet had been placed, something had clearly been dragged along the sand, leaving a trace that showed upon its surface as a scratch. What that “something” was it is difficult to say—unless, as my men declared, it was part of the membrane upon which the issulla is said to sail through the air. It could not have been caused by its tail, as it appeared in places upon both sides of the track at once.
With regard to the capacity it is said to have of being able to rise into the air from the ground, that, I think, presents but little difficulty. I gathered from my men’s account that it would have been nearly three feet long. The small fast-running lizards previously mentioned are mostly under six inches in length, and must be able to travel at nearly ten miles an hour, as it takes a man on foot all his time to catch them up. As the issulla must be five times the length of these little lizards, it is not unreasonable to assume that it can run quite twice as fast, or say at twenty miles an hour, which, if it were running against a stiffish breeze, would be equivalent to say fifty miles an hour through the air—a speed that would probably easily cause it to rise from the ground—but it is a tall story.
Snakes are very common in the desert—the lefa’a, or horned viper, and a very similar viper without horns being in places rather unpleasantly numerous. In addition we killed a very thin sandy-coloured snake, about four feet in length, which, so far as I could judge from its head, did not appear to be poisonous. The naja, or Egyptian cobra, sometimes seen in the Nile Valley, is, I believe, quite unknown in the desert and oases.
I several times heard rumours of a feathered snake. At first I put this down as being a myth, but I afterwards found that this creature had been seen by at least one European, who had been long resident in the country. The specimen he saw was one killed in the Nile Valley. He described it as being a short, stout, sandy-coloured snake, having along its back, for some distance behind its head, a sort of crest of elongated scales considerably frayed out at their ends.
The existence of this creature is by no means an impossibility, for reptiles and birds are closely related.
Insects in the desert are comparatively few in number. I once found a few small ants, pink and silver in colour. Large grotesque-looking mantids were often seen running about on the sandy portions of the desert. Some of them were of considerable size, many of them being quite three inches long. They were curious creatures, and apparently very pugnacious, as, when approached, they would often turn round and face me, raising themselves slightly on their squat fat bodies and pawing the air with their big front legs.
If I pushed my foot towards them they frequently attacked it, grappling my toe with their legs and trying to bite. I picked up one of the larger ones and gave him the end of my thumb to bite—a rather foolish proceeding, it struck me afterwards, as, for all I knew to the contrary, his bite might have been poisonous. He bit furiously at the end of my thumb with his rather formidable jaws, foaming at the mouth and doing his feeble best to damage me. He managed to get hold of a small pinch of skin between his jaws, which closed in a horizontal direction, and gave me a nip I could distinctly feel.
Once, in the desert west of Dakhla, I found a mosquito, which considerably raised my hopes that I might be getting near water. But it proved to be only a wind-born specimen, coming probably from Nesla or Bu Mungar. Lace-winged flies frequently came into our camp, even when far out into the desert, and on most nights a few moths flew into my tent and came to my candle; occasionally they were in considerable numbers.
The common house flies, though a nuisance in the oasis, are fortunately unknown in the desert, though frequently a swarm of them, if there is no wind, will follow a caravan when starting from an oasis; but they disappear in a day or two.
Once while riding in a desert with my caravan, when, having left an oasis the day before, we were considerably bothered with these pests, a swarm of which kept buzzing round our heads, I was relieved of them in a rather unexpected manner. A swallow—evidently migrating—came up to the caravan from the south, and being presumably very hungry, kept flying round and round our heads, snapping up a fly at every circle. Owing probably to its hunger, the little creature was extraordinarily tame—its wing tips several times almost touched my face. Having remained with the caravan for a few minutes, it circled round us half a dozen times to make sure that there were no flies that it had overlooked, and then flew off and pursued its way to the north.