APPEOACHING DARWIN'S VIEWS 447 
and a big one, G. nutans. I never heard of their being 
supposed to be varieties by any one, and they differ in many 
points ; but the Himal. specimens are all of an intermediate 
form — its small states identical with acanthoides, its large 
with small nutans. These facts shake species to their 
foundation — but according to my view of species, as con- 
trasted with other systematists, there are sore few of them. 
In fact if there were a possibility of bringing your and my 
opinions to hook, it might prove that we were not so far 
divided. The more I study the more vague my conception 
of a species grows, and I have given up caring whether 
the}^ are all pups of one generic type or not — that the main 
forms remain so long distinct ; that we may through their 
characters trace their distribution, is certainly all we can 
expect to prove in our day ; and the laws of that distribution 
more than we shall estabHsh in our life-time. 
I have a glorious fact for you. A tropical species of 
Cyperus ('polystachijs) and a tropical Fern, Pteris longifolia, 
grow in the hot soil of the Volcano of Ischia and nowhere 
else in Europe or the Mediterranean : see Hooker's Journ. 
Bot. for Nov. 1854, p. 351 (it is on Athenaeum table). Now 
I can wriggle out of the Fern case by allowing ubiquitous 
meteoric dispersion of Fern spores, but the Cyperus is a dis- 
gusting and detestable fact that disgusts my soul within me. 
I must however have a bite at you if I can, and so will ask 
why if the Cyperus and Pteris got there no other migrants did ? 
March 2, 1855. 
I am going on with the Tasmanian Flora and find the 
subject very interesting. Some of the scarcest and most 
local Alpine plants reappear on the isolated summits of the 
Australian Alps, and thence too I have the English Sagina 
'procumbens, which, as far as I know, has not been found 
in the South Hemisphere, except in the Falklands (this 
wants study though). T am also preparing as I go on for 
a general work on Geogr. distrib. of the whole AustraHan 
Flora— this is ambitious, but it is really the most extra- 
ordinary thing in the whole world. The Flora of Swan 
Eiver, i.e. of extratropical S.W. Australia, will I believ 
turn out to be the most peculiar on the Globe and specificalh 
quite distinct from that of N.S. Wales— also generically to a 
much greater degree than any two similarly situated areas. 
