the Charlonia group of the genus Anthocharis. 531 



Mr. Mathews, comparing certain features in the 

 Algerian flora,* informs us that there are in Algeria 

 272 species of Oriental plants not occurring in Sicily ; 

 and he further goes on: — "The question is by what 

 route did they travel between North Africa and the 

 Levant ? If we examine the eastern distribution of 

 these species we shall find that many of them occur in 

 Greece, European Turkey, East Germany, South Russia, 

 Asia Minor, and Syria, or some of these countries ; 

 others again in Egypt, Arabia-Petrsea, and Arabia, the 

 remainder in both these regions. At least half of the 

 272 species are absent from the southern side of the 

 Levant, and must have migrated from the north of the 

 Levant and North Africa, or vice versa. Among the 

 species which have travelled along this line, but have 

 not passed into Europe, one may be particularly men- 

 tioned, one of the most interesting in its distribution, 

 as it is one of the noblest of the creations of the 

 vegetable world, — I mean the cedar of Lebanon. This 

 magnificent tree, which unhappily may be said to linger 

 rather than flourish in the Algerian Atlas, is found 

 scattered in scanty patches in several parts of the chain, 

 but nowhere in abundance except at Batna, and in the 

 celebrated forest at Teniet el-Haad. The Atlantic cedar 

 is a distinct variety of the cedar of Lebanon, and has 

 been described under the name Cedrus atlantica. The 

 nearest point to North Africa where the cedar is again 

 met with is on the mountains of Cyprus, where it was 

 discovered by Sir Samuel Baker in September, 1879. 

 Sir Joseph Hooker considers the Cyprus cedar another 

 variety of the cedar of Lebanon, and names it var. 

 hrevifolia. Another cedar nearly allied to the Cedrus 

 Libani is the Cedrus dcodara of the Himalayas. The 

 differences in race in the Algerian, Cyprus, and Lebanon 

 cedars imply a great lapse of time since their habitats 

 were severed. 



" One explanation, and one alone, will account for these 

 phenomena of distribution. Sicily, geologically speaking, 

 is of very recent origin. Before its existence the ranges 

 of the Atlas must have extended into Greece. It is not 

 necessary to suppose that the cedar and other species 

 travelled in a direct line between North Africa and Syria, 



* ' Flora of Algeria,' p. 30, by Wm. Mathews, M.A., F.E.S. 



