212 THE GEOLOGICAL SUKVEY 
His visit to the Forest of Dean, in company with the brother 
of his old friend Thomas Thomson, whom he picked up at 
Bath, invahded from India, precluded a pleasant ' touch at 
recent botany in W. Ireland ' with Harvey and Ward, who 
had been making various ' finds ' ; and he writes to the former 
(August 7, 1846) : 
I do long intensely to go to the field with you and 
especially to take the water. Well done, Ward, but I 
won't knock under, having youth on my side and better 
eyes. I look forward to no greater pleasure in British 
Botany than to see the Delesserias growing in Ireland as 
they did at Cape Horn, and under such perfectly similar 
conditions. I want to see how the Antarctic seaweeds are 
replaced on the British coast ; and no one can do it to my 
satisfaction but myself. (Pretty well that for a Tyro.) 
However, a future visit to Dublin seemed possible if an 
Irish collector should have to be appointed in connexion with 
the Geological Survey scheme to form a complete British 
Herbarium with special reference to the distribution of species. 
I have persuaded Sir H. that no results can be obtained 
as to dependence of plants on soil, till a good many complete 
floras of counties with different formations are formed ; 
he and I draw well [together], by reason of his profound 
ignorance of Botany. He has an idea that the difference 
of the vegetations of the sandstone and limestone is some- 
thing more marked than between Lat. and Lat. 90 or the 
top of Ben Nevis and low water at Roundstone. 
To Mr. Bentham he writes (September 13-25) of his re- 
searches in fossil botany, the interest of which grew 
as the impossibility of relating all but the Ferns of the coal 
strata to any existing Nat. Ord. becomes more evident. 
Hitherto the collections formed are not large, as such are 
only to be obtained to any extent by employing men about 
the pits, but I have been grounding myself underground 
in the elements of the study by noting the conditions of 
their preservation and their association, so as to know 
what of the various broken pieces belong to the same genus 
