( 4R7 ) 



one sino-le young Betoum. He made out that no yonug tree eonld ever grow np, 

 Ijecanse their short roots were not able to reach the damp, deep, clayey layers out 

 of wliich the large old trees still took water, their life-element, and that therefore 

 they were destined to perish, on account of the ever-increasing aridity of the 

 desert. AVhether this ever-increasing sterility be a fact or not, the Betoums are 

 now, thirteen years later, quite strong and healthy, and young ones in every stage 

 were fonnd. 



The life-history of these Betoums is most peculiar. The seed cannot grow 

 up, or at least the yonng plant has no chance whatever to live, unless it is 

 sheltered against the inclemency of the climate — cold or hot winds or driving 

 dust and sand ; and the teeth of the camels are also to be taken into account, 

 though these "ships of the desert" are not so very numerous in this region of 

 the Sahara. 



The necessary shelter is found in the prickly Zizyphus-bushes ! In the midst 

 of them or under their branches the seedling can grow up sheltered and safely ; 

 the young tree grows to the height of its involuntary host, grows up be3-ond 

 it, commences to develop a crown, and by the time it is large enough to be 

 independent of the prickly bush, liegins to kill the latter, which cannot live in 

 the shade. 



This reo-ion of the dayats is, like all the country passed since Boghari, more 

 or less high ground, generally about Ti.lO metres above the level of the sea. At 

 the largest of the dayats, Tilrhempt or Tilghempt* (PL XXV.) known for its able 

 cook, the keeper El Aid ben Massaoud, we found tolerable rooms and remained 

 there four days. The dayats were not found as rich in bird life as we had expected. 

 Perhaps the only birds nesting in them now are a great many Scops-owls, very 

 many Crate/vj/us fidcus, some Lanius e.rci(bUor elegans, a few Athene noctiui 

 glaux, Ravens, Kestrels, and a small number of Sturnus unicolor. 



At present many species passed through on their migration to the north. 

 We observed or obtained : Falco subhiiteo jugni-tha, Cuculus canoius, numerous 

 Ilirundo urbica, Chelidon nistica, Riparlii riparid, Motacilla Jura Jhva, Lanius 

 senator, Mitscicapa hypoleuca and striata, several species of Phylloscopus and 

 Sykia, Emberiza hortulana, Milvus korschun, Coracias gurnda, Merops persicus 

 chrysocercui<, Cnlmnba oenn.s, Cpnpa epops, and Caccabis petrom spatzi. We do 

 not think that any of these birds would stay to nest, though of the Hobby we are 

 not sure. Golden Eagles, which were common in Tristram's time, are unknown. 

 Sparrows nest in the buildings of the bordj, and in the surrounding desert are 

 found some Houbara-Bustards and Sandgrouse (? species), both species of 

 Crested Larks, Otocorys bilop/ia, Ammomanes phoenicura arenicola, farther away 

 doubtless also Tthamphocorys clot-bey, and Oenaiithe moestn. 



While driving from one dayat to another Dr. Nissen said he saw a curious 

 greenish bird. Hartert seeing something moving, fired, and killed a huge, beauti- 

 fully coloured specimen of Uroma.tti.c, the spine-tailed lizard. We were at once 

 struck with the different look of this creature to those so common near Biskra. 

 We think we must have seen a hundred or more at the latter place. Several times 

 they were seen among the rocks of the Djebel Bou Ghezal, and looked quite grey. 

 Often they were brought alive for sale, and many were always on sale, stuffed, in the 



• The latter spelling is now adopted officially and on some French maps, but one hears almost 

 ahvavs " Tilrhempt," the Arab letter expressed by our r or g sounding guttural, to our cars much more 

 like an r than a g. Formerly one re.id only Tilrhempt, and still finds it thus on most maps. 



