212 THE GEOLOGICAL SUEVEY 



His visit to the Forest of Dean, in company with the brother 

 of his old friend Thomas Thomson, whom he picked up at 

 Bath, invalided 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 Eoundstone. 



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 



