198 COLIN CLOUT'S CALENDAR. 



ice-sheet finally cleared off the face of England, our 

 islands formed for some considerable time an outlying 

 peninsula of the European continent, like Spain or 

 Scandinavia at the present day ; and over the broad 

 bridge of land which then occupied the bed of the 

 German Ocean and the Irish Sea, the plants and 

 animals of temperate Europe spread by slow degrees 

 across the unoccupied plains and valleys of the British 

 Isles. Their onward course over the land denuded by 

 the ice-sheet was undoubtedly very tardy, for many 

 species never succeeded in reaching England at all ; 

 while others, which got as far as our own island, did not 

 travel as much to the west as Ireland before the sub- 

 mergence of St George's Channel made that part of 

 Britain into a separate island. It is, perhaps, to this 

 accident of position, rather than to the exterminating 

 efforts of St. Patrick, that Ireland owes its famous 

 freedom from the presence of many terrestrial reptiles 

 and amphibians. A little later, before the advanced 

 guard of the European mammalia had fully occupied 

 our eastern coasts, the North Sea and the Straits of 

 Dover were invaded by arms of the Atlantic, and Great 

 Britain finally assumed its insular shape. Thus our 

 existing fauna and flora really represent a mere fraction 

 of the Central European species the few pioneer kinds 

 that had travelled so far on their way into the bare 

 waste before the sea cut us off from the remainder of 

 the European world. We are comparatively rich in 

 insects, birds, bats, and plants, whose wings, eggs, or 

 seeds give them special opportunities of transport across 

 the sea ; but we are very poor indeed in terrestrial 

 mammals and land-amphibians, which cannot readily 



