MEETING OF THE BRITISH ASSOCIATION. 309 
were driven southwards during the glacial period, when many of them 
changed their forms in the struggle that ensued with the displaced 
temperate plants; that on the returning warmth, the Scandinavian 
plants, whether changed or not, were driven again northwards and up 
to the mountains of the temperate latitudes, followed, in both cases, by 
series of pre-existing plants of the temperate Alps. ‘The result is the 
present mixed Arctic flora, consisting of a basis of more or less changed 
and unchanged Seandinavian plants, associated in each longitude with 
representatives of the mountain flora of the more temperate regions to 
the south of them. 
“ The publication of a previously totally unknown flora, that of the 
Alps of tropical Africa, by Dr. Hooker, has afforded a multitude of 
facts that have been applied in confirmation of the derivative hypo- 
thesis. This flora is found to have relationships with those of tempe- 
rate Europe and North Africa, of the Cape of Good Hope, and of the 
mountains of tropical Madagascar and Abyssinia, that can be accounted 
for on no other hypothesis, but that there has been ancient climatal 
connection and some coincident or subsequent slight changes of 
specific character.” 
The following were the papers bearing upon botany which were read 
at the Association, with lengthened abstracts of several of which we 
are able to present our readers :— 
H. Hennessy, F.R.S.—On the probable cause of the existence of a 
North European Flora in the West of Ireland, as referred to by the 
late Professor E. Forbes 
John Hogg, F.R.S: Re the ballast Flora of the coasts of Durham 
and Northumberland. 
Dr. J. D. Hooker, —On Island Floras. 
W. Moggridge.—On e occurrences of Lemna arrhiza in Epping 
Forest. Vide ante, p. 26 
W. Moggridge.—On e zones of the Coniferæ from the Mediter- 
ranean to the crest of the Maritime Alps. 
E. Perceval Wright, M.D.—Botanical notes of a Tour in the Islands 
of Arran, West of Ireland. 
N. B. Ward, F.R.S.—The Poor Man's Garden. 
John Shaw.—On the distribution of Mosses in Great Britain and 
Ireland as affecting the geography and geological history of the present 
Flora. i 
