1883.] on the Island of Socotra and its Becent Bevelations. 307 



feature of many plants, and also the occurrence of gums and resins, 

 which in some cases api:)ear as natural exudations in the form of 

 tears. The common desert characteristics of a glaucous grey colora- 

 tion or a hairy iDubescence mark also many of the plants. The flora 

 of this region is indeed thoroughly that of the Arabo-Saharan type, 

 such genera being abundant, as Fagonia, Cleome, ^rua, Farsetia, 

 Balsamodendron, Anticlmris, Breicena, &c. 



Leaving the plains, and jDassing to the hill slopes and valleys, 

 plant life is more vigorous, but in no place sufficiently so to call for 

 the designation of forest, nor is there anything in the way of fine 

 timber. But in the valleys, wherever there is any degree of moisture, 

 small trees of some 20 to 25 feet, with smaller shrubs packed so 

 densely as to exclude the light from above, linked together by far- 

 reaching lianes, and underlain by a thick under-scrub of fern and 

 herb, make an almost impenetrable thicket, and produce a verdure 

 quite tropical in its luxuriance. In this district the type of flora is 

 of the general tropical old-world type, having representatives of 

 such genera as Greivia, Ormocar^um, BiclirostacJiijs, Dirichleiia, Lasio- 

 npkon, &c. 



Once out of the valleys and upon the plateaux the scene is 

 3Ssentially diiferent. Wide barren stret€hes of grey limestone extend 

 3n every side uni*elieved, save by an isolated Dracaena, or tree- 

 Euphorbia of stiff erect habit, looking like the remnant of the vegeta- 

 tion of some old geological epoch ; or where a lake-like dej^ression, 

 tvith its brown earth sparingly coated with green herbage, intervenes. 

 Ajid again, reaching the higher altitudes on the granitic range, the 

 vegetation impresses one at once with its sub- temperate character. 

 The arborescent type has almost entirely disaj)j)eared. Shrubby com- 

 posites such as species of Psiadia, Pluchea, and Kleinia are found, 

 md quaint types such as those of Thamnosma Niraratliamnos 

 UmheUiferse), Ceplialocroton, Dorstenia, Adenium, &c., are frequent. 

 Twiggy, narrow-leaved herbs form a dense deep carpet on the soil, 

 nterrupted here and there by a j)rotruding lichen-covered boulder, 

 md for all the world like the covering of heather on a Scottish moor ; 

 .vhilst within the shade of the boulders, or in the moisture of the 

 )verhanging cliffs in the ravines, bright green herbs, such as s^jecies 

 )f Galium and GijpsophUa, nestle in beds of liverwort and moss, so that 

 t would require no very great effort to believe one was exploring an 

 Upine crag in a temjDorate region. 



The flora is a pretty extensive one. It comprises, as we know it, 

 iomewhere about 600 species and varieties of Ph^enogams, 20 species 

 )f Vascular Cryptogams, whilst Cellular Cryptogams number about 

 500 species. The extent of the flora is thus 900 to 1000 species. 



Amongst Phaenogams the proportion of Monocotyledons to Dicoty- 

 edons is as 1 to 6, a proportion somewhat smaller than is usual in a 

 Topical island flora, but this is due possibly, not to the absence of the 

 brmer, but because collectors have usually visited the island when 

 hey are not showing above ground. 



