FURTHER EXAMPLES loi 
Thames and Medway valley. Mr Hazzeldine Warren ' 
has described a similar and apparently contemporaneous 
Arctic bed in the valley of the Lea, to the east of London. 
Over the Arctic bed in the foundation of the Admiralty 
building, Mr Abbot found a -deep bed of gravel, con- 
taining remains of Pleistocene mammals and also a flint 
implement typical of the Solutrean culture — the culture 
following the Aurignacian, but preceding the Magdalenian. 
We have seen that in the cave at Langwith, with the 
evidence of an Aurignacian and of a Magdalenian culture, 
animals of a sub-Arctic climate were present. We are 
therefore justified in concluding that towards the close 
of the Palaeolithic period the climatic conditions were 
much colder than now. We are uncertain as to the 
causes of climatic change, but we cannot believe, from 
our knowledge of historic times, that such changes can be 
brought about except by imperceptible degrees extending 
over a long period of time. Yet, long as is the period 
which has elapsed since Arctic conditions last ceased, the 
river-bed type of man has persisted, with his body altered 
only in minor details. 
7\/o/^. — The skeleton of the Cissbury man is preserved 
in the University Museum, Oxford. Professor Arthur 
Thomson and the author have re-examined this skeleton, 
and regard the somewhat peculiar features of the limb 
bones as due to natural rather than to pathological causes. 
The recent exploration of Grimes Graves has revealed a 
mixture of cultures — of both Neolithic and Pala:olithic 
dates. 
' See Quart. Journ. Geol, T912, vol. Ixviii. p. 213. 
