152 AN ANALYSIS OF THE FLORA OF SINAL 



carried the bottom of the shallower parts of the Red Sea above the 

 surface, especially of those two arms which wash the sides of Sinai, The 

 uniformity of the lowland floras on the opposite side of the Red Sea 

 drives me to the conclusion that there was at some period much more 

 continuous land for the migration of species between Africa and Arabia 

 than there is at present, and in consequence of this community of species 

 being most observable amongst the so-called Desert forms, which are in 

 many cases, perhaps, of recent origin, and form, in fact, the existing 

 characteristic life, and because the older flora of more temperate times is 

 much, more distinct on both sides of the Red Sea, I imagine that this con- 

 tinuity of surface belongs to the more recent period. In speaking of this 

 community of flora, it is necessary to point out that a considerable portion, 

 perhaps a third part, of the Sinaitic Desert flora may be considered as 

 belonging specially to the neighbourhood of Sinai, almost confined, in 

 fact, to Arabia Petrsea (which includes Sinai and South Palestine) and 

 Egypt. So that it seems fair to regard Sinai, or perhaps more properly 

 the Delta, as a centre of dispersion for a considerable number of Desert 

 forms. It is usually conceded that, at the close of the glacial period, the 

 temperature kept on increasing to a greater point of warmth than has 

 since prevailed. With sufficient atmospheric moisture, and sheets of 

 fresh water gradually diminishing, no doubt, with an increasing heat, 

 Sinai, open to southern visitors both from Africa and Arabia, must have 

 been well stocked with what we now consider tropical or sub-tropical 

 forms. In the Wady 'Arabah, for example, two large saline lakes, at 

 least, existed, and its sides were probably fringed throughout with such 

 woods as now exist in a reduced condition only in the Gh6r es Safieh, In 

 the drier parts the progenitors or ancestral types of the present highly- 

 modified Desert forms spread rapidly. When I come to analyze the flora 

 of the Ghor es Safieh, these remarks will obtain greater force. It will be 

 seen that the majority of tropical forms surviving there on account of its 

 peculiar condition are Nubian, and have probably arrived thither by way 

 of the 'Arabah. 



To illustrate the Arabian — for we may presume that most of the 

 Persian Sinaitic plants are also Arabian — character of the Sinaitic 

 Plateaux flora, I may mention that the following species, believed peculiar 

 to Sinai, were found by me on Mount Hor on the western skirts of the 



