176 
THE GEOLOGIST. 
which they are covered^ he was of opinion that great changes in 
the levels of land and sea must have taken place, to account for 
the existing phenomena. On this point nearly all geologists 
were agreed : what they differed about chiefly was, as to whe- 
ther those changes had been owing to the subsidence and eleva- 
tion of the land, or to an influx and retrogression of the sea. 
Having entered at some length into a consideration of this in- 
teresting branch of the subject, he summed up by stating, that 
the conclusions to which he had arrived were : 1st, " That there 
existed around the once more extensive shores of the island of 
Great Britain, and in many parts in the interior of the country, 
forests of hardwood, some of great dimensions, and an under- 
vegetation of shrubs and grasses, similar to the flora of such 
species as are now growing on the present surface ; but which 
are now either entombed by drifted gravel or sedimentary sand, 
silt or clay, and are, more or less, washed over or covered up by 
the surrounding tides and deep sea ; or else they are buried over 
by mosses and peat bogs, the growth of subsequent ages. 2nd, 
That, in addition to the fauna of the present day, the animals 
which inhabited these primeval forests were the gigantic elk, the 
hos uruSj or auroch, now only found in the forests of the Crimea, 
the bear and wolf ; if not the elephant, tiger, rhinoceros, and 
hysena. 3d, That the period in which those primeval forests 
once lived and grew in pleno aere was post pliocene, and imme- 
diately anterior to the last notable geological change that has 
generally affected the surface of our island. 4th, That a gra- 
dually increasing higher level of the sea towards the summits of 
our highest hills was the first p^:ocess of the submergence of 
these forest beds, littoral and landward ; and their subsequent 
entombment in the lower levels was owing to the greater or less 
delay in the subsidence of the water level — producing di'ift from 
quick secession from the higher grounds, and allowing of sedi- 
mentary deposits on the lower, from intermittent and slow sub- 
sidencies, till nearly the present levels have been obtained. 5th, 
