634 THE JOUENEY TO PALESTINE 
remarkable forms especiallj^ 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, 
Acant]wli7non, 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 pecuHar 
to the elevation but w^hich 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 
teUs 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. 
