117 



The knowledge that we at present possess as to the rate of the 

 formation of peat is but imperfect. Much depends upon the con- 

 ditions under which it is formed, and in the present instance 

 we are without definite evidence to guide us. There cannot, 

 however, be much doubt that a long period would be required 

 to form 14 feet — for a large tree to grow on the edge of it to the 

 size I have mentioned — and further, that the slow accumulation 

 of 8 feet of silt, which shews no trace of having been brought 

 by violent water action, would be considerable, and afterwards 

 we must not lose sight of the silt itself being in places slightly 

 covered by soil and gravel. 



In further confirmation of its antiquity, I would particularly 

 call attention to the section which shews that long since the bed 

 was formed the drainage of the country must have been changed, 

 as is evidenced by Holly Hazle brook. Until the excavations 

 had made considerable progress, I thought the peat bed was 

 supplied with moisture by Holly Hazle brook, such, however, 

 was clearly not the case, as the little rivulet cuts the silt bed 

 above it at right angles, and does not reach the peat itself. 



A recent distinguished French writer, M. Belgeand, in his 

 work* "La Seine" says, "The Quaternary period of the Seine 

 basin is coeval with the Glacial period," and he considers that 

 it was brought suddenly to a close with the low level gravels. 

 To this Quaternary period the peat deposits immediately succeed, 

 owing to the suddenly diminished rainfall leaving the rivers 

 clearer and under conditions favourable for the growth of peat, 

 which, he shews, never takes place in river valleys subject to 

 frequent and heavy floods, but always in valleys where springs 

 abound and the floods are few and not turbulent. 



Sir Charles Ltell states, '^That if all the littoral sunk 

 forests of the South and West of England are referable to about 

 the same Geological period, the occasional presence in them 

 of the Mammoth will entitle them to be regarded as very 

 ancient, or of a date intervening between the era of the lake 

 dwellings and that of the oldest epoch to which man has yet 

 been traced back." 



* " Nature," March 14th, 1872. 



