By the Rev. John Adama. 



277 



vegetation as we now find on the bleak wastes of Siberia; whilst the 

 old races of animals succumbed to the rigour of the climate, and 

 were succeeded by mammals and ruminants, akin to those which 

 inhabit the northern regions. A change almost analagous to a new 

 creation, must have taken place in the fauna and flora of this region 

 of the earth, between the era of the Bagshot sands, and the 

 commencement of the drift deposit; for we find, embedded in the 

 latter, organic remains totally different in species from those which, 

 the former contain. But how were those masses of drift or gravel 

 spread over the surface of the country ? A subsidence of the land 

 must again have taken place, admitting the ocean once more to its 

 ancient bed ; and to this inundation the earliest of our superficial 

 gravel deposits may be traced. The submergence must have been 

 of long duration, and accompanied with swift currents ; for in many 

 parts of this vicinity, it has completely broken up the tertiary strata, 

 and has strewn the ground not only with enormous masses of flints 

 and silt from the adjacent chalk hills, but with pebbles from the 

 Thanet sands, ochreous debris from the London clay, and sandstones 

 from the Bagshot series. The annexed woodcut (fig. 2), illustrates a 

 remarkable accumulation of gravel at the north-east corner of Inkpen 



Fig. 2. — Gravel-pit on Inkpen Common. 

 a. White angular flint-grarcl. 



6. Brown flint gravel, containing large blocks of greywetUer-sandstone. 

 c. Lower Bagshot Sand. 



