CHAP. XIV. OF ENGLAND, IRELAND, AND THE CONTINENT. 283 



from the latter phase to that of map 41, and finally to still 

 greater accessions of land. During this last period the 

 passage of the Germanic flora into the British area took place, 

 and the Scandinavian plants, together with northern insects, 

 birds, and quadrupeds, retreated into higher grounds. 



The first appearance of man, when, together with the mam- 

 moth and wooll}' rhinoceros, or with the Mephas antiquus, 

 Rhinoceros hemitoechus, and Hippopotamus major, he ranged 

 freely from all parts of the continent into the British area, 

 belongs probably to a late portion of this second continental 

 period. 



Foui'thly, the next and last change comprised the break- 

 ing up of the land of the British area once more into nume- 

 rous islands, ending in the present geogTaphical condition 

 of things. There were probably many oscillations of level 

 during this last conversion of continuous land into islands, 

 and such movements in opposite directions would account for 

 the occurrence of marine shells at moderate heights above 

 the level of the sea, notwithstanding a general lowea'ing of the 

 land. To the close of this era belong the marine deposits of 

 the Clyde and the Carses of the Tay and Forth, before alluded 

 to, pp. 48, 51, 54. 



In a memoir by Professor E. Forbes, before cited, he 

 observes that the land of passage b}^ which the plants and 

 animals migrated into Ireland consisted of the upraised 

 marine drift which had previously formed the bottom of the 

 glacial sea. Portions of this drift extend to the eastern shores 

 of Wicklow and Wexford, others are found in the Isle of Man 

 fall of arctic shells, others on the British coast opposite Ire- 

 land. The fresh-water marl, containing numerous skeletons 

 of the great deer, or Megaeeros, overlie in the Isle of Man that 

 marine fflacial drift. Professor Forbes also remarks that the 

 subsequent disjunction of Ireland from England, or the forma- 

 tion of the St. George's Channel, which is less than 400 



