70 Flowers and their Pedigrees, 



the German Ocean, and the Irish Sea ? To this 

 question I am deferentially inclined to give a some- 

 what different answer from that of most of our 

 authorities. As a rule, it seems to be implied that 

 the subsidence was a single act, spread indeed over a 

 considerable length of time, but completed once for 

 all, and never since renewed. It appears to me more 

 probable, however, that the subsidence has been going 

 on more or less ever since the age of the submerged 

 forests, and that it still continues in places over the 

 same area. Mr. Wallace has already pointed out that 

 Ireland was probably separated from the mainland 

 sooner than England, because it has fewer native 

 mammals and hardly any reptiles or amphibians. 

 The happy immunity from toads and serpents which 

 is generally attributed to the pious exertions of St. 

 Patrick, may perhaps rather be set down to the early 

 isolation of Ireland from the mainland shortly after 

 the end of the great ice age, and before all the 

 members of the new European fauna had had time to 

 spread equally over the more outlying portions of the 

 yet undivided continent. But there are other indica- 

 tions of subsequent partial submergence elsewhere. 

 Many facts lead me to the belief that the Bristol 

 Channel was still a plain through which the Severn 

 flowed quietly to the sea long after the final insulation 



