46 Mr. C. Reid. The Palaeolithic Deposits at Hitchin 



we now enjoy. Mr. Mitten writes of the mosses, that " all these are 

 inhabitants of a sylvan temperate region .... and none point 

 to a different environment from that now existing ; they are not 

 arctic." The occurrence of Naias marina, now only found in Britain 

 in two of the Norfolk Broads, is singular, though the plant was 

 evidently more common in former times than at the present day. 

 It has now been discovered in the pre-glacial deposits of Norfolk and 

 Suffolk, beneath Palaeolithic remains at Hitchin, and in a submerged 

 peat of Neolithic date at Barry Docks, in South Wales. 



The resemblance of the Hitchin Palaeolithic brickearth to the 

 Palaeolithic brickearth of Hoxne, and the similarity of the old alluvia 

 beneath, both in fossil contents and in the physical changes they 

 suggest, is so striking that one is compelled to correlate them bed 

 by bed. If, however, this correlation be correct, it is evident that 

 the intermediate deposit full of leaves of Arctic willows, so con- 

 spicuous over part of the area at Hoxne, is missing at Hitchin. At 

 •each locality the same story is told. Some time after the passing 

 away of the ice the land stood higher than now, so that the streams 

 had a greater fall and valleys were cut to a somewhat greater depth. 

 Then the land sank and the valleys became silted up with layer after 

 layer of alluvium, to a depth of at least 30 feet, the climate remain- 

 ing temperate. The next stage, when an arctic flora reappeared, is 

 only represented at Hoxne. The third stage in the infilling of the 

 valleys is shown in the curious unstratified decalcified brickearth 

 with scattered stones and Palaeolithic implements, identical in char- 

 acter at Hitchin, Hoxne, Fisherton, and other localities, which 

 irresistibly suggests a mingling of wind-transported material and 

 rainwash. 



It may be pointed out that if this hypothesis of the origin of the 

 Palaeolithic brickearth during the reign of "steppe" conditions be 

 accepted, it will account for the non-correspondence of the ancient 

 channels with the present valleys, a thing very difiicult to explain if 

 the infilling were caused by ordinary fluviatile action. If the Palaeo- 

 lithic brickearth is equivalent to the Palaeolithic loess of the ancient 

 deserts in central Europe, we can understand how during this period 

 of cold drought the smaller streams ceased to flow and their valleys 

 became so filled with rainwash and dust that when a moister climate 

 recurred the streams had to seek new channels. 



