8o PROCEEBrNGS OF THE 



England and AVales, that we are indebted for our present 

 extensive knowledge of them. Mr. Iteid has determined the 

 occurrence in the glacial deposits of no less than 130 species of 

 plants, nearly a tenth of our existing flora. No doubt this 

 number represents only a portion of the plant-forms which took 

 possession of our country as its ice-covering disappeared, but 

 it is sufficient to convey to us a fair idea of the facies of that 

 vegetation, and to supply material for correcting erroneous 

 views as to the origin of our Flora, as well as to afford data for 

 the more intelligent prosecution of such an investigation. 



The question of the Greographical Distribution of the plants 

 of our existing Flora was taken up in early life by Hewett 

 Cottrell Watson, and became the subject of investigation during 

 his long and active life. His mental constitution singularly fitted 

 him for collecting and sifting the innumerable details which 

 were brought together in his various works. He was cautious, 

 logical, and unimaginative. He had no theories to support. His 

 only object was to present the facts to students in such a form 

 that they would tell their own story. The publication of his 

 ' Cybele ' is rightly regarded by De Candolle as an epoch in 

 the history of Botany. 



His grouping of the plants so as to show their geographical 

 relations was based on the distribution of the plants in Britain, 

 and had no relation to exotic floras with which they might 

 have any special affinities. He established six groups : — (i) The 

 British Type, containing species widely spread throughout 

 Britain ; (2) The English type, including those found only in 

 the Southern part of the Island ; (3) The Scottish type, those 

 found in the Northern part ; (4) The Highland type, containing 

 the alpine plants ; (5) The Grermauic type, those found in the 

 East of England ; and (6) Tlie Atlantic type, those growing only 

 in the West of England. These various groups do not represent 

 any relationship other than that of Greographical Association. 



Edward Forbes devoted his attention to the Greographical 

 Distribution of British plants, and published in 1840 his im- 

 portant memoir ' On the connexion between the Distribution 

 of the existing Fauna and Flora of the British Isles and the 

 Geological Changes which have affected their area, especially 

 during the Epoch of the Northern Drift.' He sought to 

 discover the sources from which the existing assemblage of 

 plants in the British Islands had been obtained, and the means 

 by which they were transported to their present localities. He 

 detected the presence of five well-marked Floras making wp the 

 existing vegetation : — 1. The group of Peninsular plants found 

 in the West and Suuth-west of Ireland. 2. The plants of the 

 Channel Islands and tlie North-west of France occurring in the 

 South-west of England and the South-east of Ireland. 3. The 

 plants of the North-east of France growing on the opposite 

 shores of the English Channel in the South-east of Enofland. 



