218 BOTANICAL INFORMATION. 
phonolith and amygdaloid, containing zeolite, feld-spar, and chalcedony. 
in all directions, though rarely in solid masses on the surface, but 
mostly covered by volcanic tuffa and trasse, (trap?) including numerous 
shells. In boring for water at a considerable depth under the crumbling 
lava, they have been obliged to desist on account of the hard trap 
(basalt) which was encountered. The few wells that are in the valley 
have only yielded a fair permanent supply of water at a depth of 103 
eet. 
The indigenous plants are, on account of the aridity of the ground and 
air, limited to a few of the desert. Cultivation is out of the question, 
for want of means of irrigation. The largest tree is Sterculia urens, 
which occurs sparingly in the deep recesses on the western shore. 
Poinciana elata and Acacia planifrons appear, likewise, of considerable 
size, in bays of difficult access. Most of them are felled at an early age; 
Balsamodendron Opobalsamum, Euphorbia triaculeata, Capparis carnosa, 
Cadaba glandulosa, continue shrubby, covering beds of torrents; Cassia 
lanceolata and angustifolia, Gynandropsis pentaphylla, Cleome angusti- 
folia, Anastatica Hierochuntica, Psoralea bituminosa, Indigofere spet., 
Staticis spec., are among the scanty, stunted vegetation, which is met 
with in more protected situations, affording some appearance of verdure 
during one half of the year. Corn and vegetables, as well as fodder, 
have all to be imported, partly by sea, from the African coast, and 
partly, in times of peace, from the continent. The coast to the west- 
ward is less barren than Aden; here are seen groups of palms and of 
shrubs consisting probably of Rhamnus Napeca, and Acacia planifrons. 
The Akrabbi-Bedouins pursue some sort.of agriculture far inland, out 
of the produce of which they carry to Aden the grain and straw of the 
Durrha. Excellent grapes ripening in May, oranges, lemons, figs, 
plantains, and dates, are brought from a short distance from the town 
of Lahadsch, to the north-west of Aden, where market supplies are 
early improving. The great demand and the lucrative sale of the 
produce at Aden have already had a most beneficial influence on the 
neighbouring Bedouin tribes. 
The number of land animals and birds is still more limited than that 
of plants, with the exception of very troublesome rats, mice, and sea- 
