534 THE JOUENEY TO PALESTINE 



remarkable forms especially generic do appear very suddenly 

 in great quantities, and am inclined to believe that the 

 lower limit of these is far better defined than the upper 

 limit of those that disappeared. This applies to Astragalus, 

 Acantliolimon, Vicia, and several other plants which are 

 characteristic of the dry soil and climate that prevail above 

 7000 ft., but not to other plants which are equally peculiar 

 to the elevation but which depend on some little moisture, as 

 Potentilla, &c. The vegetation above 8000 ft. was extremely 

 scanty, and I found but one Alpine or Arctic plant (Oxyria 

 reniformis), and that was close to the tip- top and very rare. 

 This absence of Alpine plants on the mountains of Asia 

 Minor is a very characteristic feature, and is shared, I am 

 assured, by the mountains of Algeria. Under these circum- 

 stances the presence of so very marked an Arctic plant as 

 Oxyria is very interesting — it seems to say that an expulsion 

 of other Arctics must have taken place, and the drought 

 would effect this well enough. 



The Cedars are going owing to the same causes. Every 

 seedling dies, there are no trees under 40-50 years old, 

 from which ages up to 500 (perhaps the oldest) there are 

 trees of all (or many) ages. 



Though the last of the Southern Floras was now published, 

 1860 did not bring a hoped for lull in the press of work ; pressure, 

 if anything, increased ; official work at Kew, both correspon- 

 dence and practical administration, grew steadily ; the Linnean 

 and other learned Societies made considerable demands upon 

 him ; to his own work he was always ready to add investigation 

 and experiment for Darwin, especially on the fertilisation of 

 perplexing Orchids, their structure and homologies, and the 

 rationale of the curvature of the style in obhque flowers. As 

 a successor to the Antarctic Flora he was now deep in the 

 Arctic Flora, examining, comparing, speculating, and, as he 

 tells Asa Gray (June 26, 1860), 



horribly stumped by so many inosculating groups in 

 America and Europe. What a deal there is to do in redoing 

 N. temperate Flora ... I can only account for pecuHarity 

 and paucity of Greenland Floras by plants having been 

 driven out by Glacial cold and never got back. 



