OEIGIN OF LOCAL FLORAS. 
35 
could have conveyed them from the mountains of Spain to 
those of Ireland ; nor can we suppose the little seeds of the 
saxifrages and ericas to have been conveyed through the air, 
as they are not adapted for this mode of dijBPusion ; and, in 
addition to this, plants with winged seeds, belonging to the 
natural order Gompositcey intermingled with these saxifrages 
and ericas in Spain, are not present with them in Ireland. 
Either, therefore, we are driven to adopt the hypothesis of the 
separate and independent creation of these plants in the two 
localities, or we must believe that Spain and Ireland were 
formerly united, and that they migrated before the two coun- 
tries became separated from each other. Now, is there any 
geological evidence of this anterior union of Spain and the 
west of Ireland? 
Professor Forbes thinks that there is. He grounds his 
opinion on the discovery of beds of marine deposits in the 
mountains of the Taurus, in Turkey, at elevations of from 
2,000 to 6,000 feet above the present level of the Mediterra- 
nean. From their nature and position it is inferred that, at 
the end of the Miocene Epoch, the region about the Mediter- 
ranean underwent great changes, and the bed of a sea which 
extended from Greece to the Azores was gradually elevated. 
A vast continent extended from the Mediterranean to the 
British Isles, and all that part of the Atlantic which now 
washes the western shores of Europe was converted into dry 
land. It was at this tim^ that Ireland was united to Spain, 
and the Archipelagos of the Canaries, the Azores, and the 
Madeiras, were probably contiguous in the same manner. The 
dozen or more plants found on the mountains in the west of 
Ireland are supposed to be the remains of the flora of this 
ancient continent, which have survived to the present day. 
Its existence is indicated by the fact that the plants of the 
Canaries and the Azores are all one . flora, the species being* 
sometimes the same as those in the Asturias and the west of 
Ireland, but more often identical with the plants of Spain, 
Sicily, and Syria. 
Another argument adduced is the existence of a semi-circular 
belt of gulf-weed (Sargassum hacciferum), ranging between 
the 15th and 45th degrees of north latitude, which is well 
known to be a sea-shore plant, and as it is constant in its posi- 
tion, it is supposed to be attached to this ancient coast-hne, 
now submerged, and to indicate its former extent and 
position. 
It was during this era that the plants of the Asturias and 
those of the Armorican type migrated from Spain to the west 
of Ireland, and from the French coasts of Brittany and Nor- 
mandy to the south-east of Ireland and the south-west of 
D 2 
