70 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 
other plants which are identical with species found abundantly 
in the north of Spain ; (2) another local flora in the south-west 
of England and south-east of Ireland, resembling the vegetation 
of the Channel Isles and north-western France ; (3) a restricted 
flora found on the chalk downs of the south-eastern counties. 
of England ; (4) a remarkable though limited flora, flourishing 
on the tops of the mountains, chiefly in Scotland, but also 
on the hills of Cumberland and Wales, and even on some 
uplands in Ireland, in which vegetation all the plants are 
specifically identical with Scandinavian forms; (5) and last, 
a general or Germanic flora, like that of Central Hurope, 
everywhere present either alone or mingled with the others. 
Forbes accounted for this distribution of the flora by 
migration or colonisation from neighbouring lands previous 
to the isolation of the British Islands from the rest of Europe. 
He supposed that the southern parts of our islands were 
probably not submerged under the glacial sea, and that 
over land now covered his three southern assemblages of 
plants may have migrated successively northwards from 
Spain and from France, before, during or after the Ice Age. 
If the floor of our seas was raised by even 100 fathoms, the 
British Isles would become a part of the European continent, 
the North Sea would become a great plain continued south 
and west through what is now the English Channel, and a 
strip of land would run from Britain along the west coast 
of France so as to jom the north of Spain. This was the 
“Continental Platform” over which, according to Forbes, 
the plants, and even possibly some of the lower land animals, 
may have migrated into the south and west of Ireland. 
The fauna of our seas also, like the land flora, presents 
distinct northern and southern relations. This is clearly seen 
both amongst the invertebrata, such as the molluscs, and also 
amongst fishes. In discussing these relations, one of the most 
interesting points that Forbes demonstrated was the presence 
