3H 
appeared at the close of the glacial period which ushered in the Post 
Tertiary or Quarternary period of our earth's history. 
The neighbourhood of Bristol has not undergone much change since the 
chalk age. The land near the Cotteswolds and the Mendips was probably 
dry during the Tertiary period, for I believe no discovery has yet been 
made of any Tertiary remains, whether fossil or deposit. When the great 
subsidence of the northern half of England took place, admitting its 
surface to be over-spread with the Arctic Ocean and obscured with ice and 
icebergs, a great change in the mean sea level doubtless took place in the 
south and western parts which escaped the ravages of the Northern Sea. 
Then the waters of what is now the Bristol Channel most likely reached 
the foot of the Mendip and Cotteswold Hills, and washed the sides of the 
innumerable islands that appeared above the waves — such as Glastonbury 
Tor, Dundry, Ashton, Clifton, &c, which then were completely isolated 
from the main land. The Atlantic water covered the moorlands of 
Middlezoy, Sutton, &c, for in many places we find deposits containing 
Mollusca similar to those existing at the present time. 
Gradually, however, the land rose again, and became covered with 
dense forests, which once covered the country, and extended over much 
of the tract now under the sea, and which at very low tides we may at any 
time examine. These trees, as now, were the Oak, Elm, Hazel, Beech, 
&c. ; and although soaked by the salt water, and being the homes of the 
Pholads, still shew their structure in the clearest manner. In the open 
spaces, gradually and naturally, extensive morasses and bogs appeared, 
giving appropriate shelter to the Rhinoceros. The rivers from the water- 
shed of the neighbouring coast brought down accumulations of sand, mud, 
and gravel, from the Oolite and Cretaceous surface towards the sea. 
The tidal action, as we know it would, opposed this flow and formed a 
bank, thus building up as it were a huge lake. The remains of this are 
now visible in the great peat and turf beds of Bridgwater and Burnham. 
At this time, the animals whose remains we now find in the bone caves 
of Banwell, Wookey, Loxton, Hutton, &c, flourished. Among many 
others we have recognized the Rhinoceros, Cave Lion, Hyasna, Elephant, 
Wolf, Musk Sheep, and Elk. It was formerly thought that these animals 
flourished in the Eocene period, which is known to have had a sub-tropical 
climate, and were killed by the cold of the glacial period, and that their 
remains are those we now find fossil. It is, however, more probable that 
although this was the case with some species, yet others struggled on for 
a long time afterwards, until they became contemporaneous with man. 
