ScHAHFF — On the Origin of the European Fauna. 487 



of the year the same tract of ground as is now the case with the elks 

 and reindeer. Since, however, as Mr. Lydekker tells us (p. 300), " it 

 has now been ascertained that the remains of both tropical and Arctic 

 forms have been found lying side by side in the same bed, it is per- 

 fectly certain that such an explanation will not meet the exigencies of 

 the case." 



The land and freshwater mollusca known from the Forest-bed are 

 not Arctic, as one should have expected from the foregoing account of 

 the migrations. According to Mr. Clement Eeid (72 a, p. 186), of the 

 fifty -nine species now determined, forty-eight are at present living at 

 Norfolk, six are extinct, two are Continental forms living in the same 

 latitude as Norfolk, and the other three are southern forms not now 

 living in Northern Europe. The flora also is not Arctic. 



Looking at the fauna of Ireland as a whole, there seems no reason 

 to suppose that the whole of it could not have reached Ireland at or 

 just previous to the time when the Forest-bed was deposited in the 

 manner I have attempted to explain in the preceding pages. But 

 since there is very strong geological evidence to show that a Glacial 

 Period, accompanied by an immense sheet of ice which covered the 

 greater part of the British Islands, succeeded the Eorest-bed Period, it 

 is perfectly clear that the present fauna could not have survived it in 

 the country. 



Mr. Clement Eeid believes that a large portion, probably most, of 

 the native British plants were exterminated during the Glacial Period, 

 to be reintroduced when the climate ameliorated (72 c, p. 182). 

 " With glacial conditions in Scotland and the hilly grounds of Eng- 

 land and Ireland," remarks Prof. James Geikie, " neither temperate 

 flora nor fauna could have existed in our country" (S5 e, p. 169). 

 According to Dr. Wallace, the fauna was destroyed during the Glacial 

 Period by a submergence (89, p. 338). 



Whether the destruction of the fauna and flora was caused by ice 

 or water matters little. Almost all British geologists and zoologists 

 are agreed that the bulk of the Irish fauna and flora migrated to Ire- 

 land after the Glacial Period, because they are somehow or other con- 

 vinced that it must have been destroyed had it reached the country 

 before that period. I have mentioned before that I do not share these 

 views, and I have shown that the range of species within the British 

 Islands is incompatible with the notion of a repopulation after the 

 Glacial Period. "There are few points," says Prof. J. Geikie {35c, 

 p. 169), " we can be more sure of than this, that since the close of 

 the Glacial Epoch — since the deposition of the clays with Arctic shells 



