it LLOYD'S NATURAL HISTORY. 



as the conditions were the more favourable to the one or the 

 other. 



6. A period of severe glacial conditions, with glaciers and 

 coast-ice, chiefly affecting Scotland, and the north of England 

 and Wales. 



7. Period of the retreat of the ice, when a few mountain- 

 glaciers alone remained, and Britain was probably insulated. 



8. Britain again continental ; summer and winter tempera- 

 tures more excessive than now ; great forests largely prevalent. 

 Incoming and spreading of the existing fauna. 



9. Period of final insulation of Britain ; the climate being 

 moist, the great forests tending to disappear, and peat-mosses 

 prevalent. 



10. The present condition of things. 



Whether, therefore, the disappearance of the continental 

 fauna in Britain be attributed to submergence or to the direct 

 action of the ice-sheet, it will be apparent that both Mr. 

 Wallace and Professor Geikie are at one in considering that 

 Britain has been connected with the Continent at two distinct 

 epochs, and that the present fauna did not make its appearance 

 till the second continental period. 



While admitting that both these high authorities are right in 

 regard to the disappearance of the original continental fauna 

 from the greater part of the islands, Mr. G. W. Bulman/ 

 however, in a paper contributed to Natural Science for 

 October, 1893, disputes the contention that its disappear- 1 

 ance was total, and consequently urges that there is no need 

 for a second connection with the Continent after the first 

 severance. 



This writer bases his contention of the survival in our 

 islands of a part of the original fauna from the southern extent 

 of the ice during the period of maximum intensity of the 



