84 APPENDIX C 



APPENDIX C. 



P. 27. The following are the main points relied on in the 

 explanations that have been suggested to account for the origin 

 of the " Head," together with some of the objections to them. 



1. That the Head is due to excessive rainfall. The absence 

 of water channels and of water-worn materials are objections to 

 this view. 



2. That, during the Glacial period, ice and snow sliding down 

 the surface of the hills carried with them the surface debris 

 which it deposited at lower levels. This is open to fewer objec- 

 tions, but the gradients are in general too small, and it fails 

 to account for the condition of the organic remains ; and it is 

 difficult to conceive that a surface thus planed off should afford 

 sustenance to the class of animals and molluscs found in the 

 rubble; nor have the proposers of this explanation given any 

 instance in which the same general conditions obtain in cold or 

 arctic districts at the present day. 



3. A wave of translation, such as suggested by Sir Roderick 

 Murchison, also fails to embrace many of the observed results, 

 though it accords with the angularity of the debris. 



4. To severe cold and fluviatile agency ; but there is no evidence 

 of river action, no wear by Tolling, no concordance with the topo- 

 graphical conditions, 1 and no fluviatile remains. 



APPENDIX D. 



P. 33. The Soinme district affords excellent illustrations of 

 the successive stages of the valley drift deposits ending with the 

 Rubble-drift and Alluvial beds ; we there find 



First and oldest. The high-level gravel of St. Acheul, Amiens, 



* The objections are more fully stated iu my paper on " Raised Beaches, " 

 Quart. Journ. Oeol. Soc., Vol. xlviii., pp. 326-328. 



