Revieivs — Ansted on the Weathering of BocJcs. 25 



same race of nomadic hunters, who at first could use it merely as a 

 rendezvous, where they came to share the spoils of the chase taken 

 in the neighbourhood ; but coming again they made a more perma- 

 nent occupation, until their accumulated refuse and the debris gradu- 

 ally raised the floor of the cave, leaving the inconvenient height of 

 only 1"20 metre (about 4ft.) between it and the roof; and then they 

 abandoned it by degrees, returning once more at last to conceal 

 their dead there. No longer accessible, except perhaps to the foxes 

 above noticed, this shelter and its strange sepulture were slowly and 

 completely hidden from sight by atmospheric degradation bringing 

 down the earthy covering, which, by its thickness alone, proves the 

 great antiquity of the burial in the cave. 



" The presence of the remains of an enormous Bear, of the Mam- 

 moth, of the great Cave-Lion, of the Eeindeer, the Spermophile, etc., 

 in the hearth-beds, strengthens in every way this estimation of their 

 antiquity ; and this can be rendered more rigorously still if we 

 base our argument on the predominance of the Horse here in com- 

 parison with the Eeindeer, on the form of the worked flints, and of 

 the bone arrow and dart-heads, and on the above-mentioned indica- 

 tions of hunting, as well as on the absence of any engraving or 

 carving. Hence we may refer this station of Cro-Magnon to the 

 age immediately preceding that artistic period which saw in this 

 country the first attempts of the engraver and the sculptor." 



He writes, at p. 70, " Amidst the human remains lay a multitude 

 of marine shells (about 300), each pierced with a hole, and nearly all 

 belonging to the species Zittorina litorea, so common on our Atlantic 

 coasts. Some other species, such as Purpura lapillus, Turritella 

 communis, etc. occur, but in small numbers. These also are per- 

 forated, and like the others, have been used for necklaces, bracelets, 

 or other ornamental attire." etc., etc. Amulets of ivory were also 

 found. 



The perforated shells, bone implements, flint flakes, etc., form the 

 subject of the six excellent plates accompanying Part YH. 



in — On some Phenomena of the Weathering of Eocks, illus- 

 trating THE NATURE ANB EXTENT OF SuBAERIAL DENUDATION. 



By D. T. Ansted, M.A., F.E.S., &c. 



[From the Transactions of the Cambridge Philosophical Society. Vol. xi. 

 Part II. 1868] 



PEOF. ANSTED here brings forward a number of personal 

 observations on the influence of rain, frost, extreme heat and 

 dryness, and of vegetation acting with the atmosphere in certain 

 cases, in modifying the earth's surface. 



Fissures produced in rocks, during long continued dry weather, 

 are more extensive and influential than is generally supposed. 

 Valleys "two or three hundred feet in depth, miles in length, and 

 several hundred yards wide," have originated in cracks, and been 

 gradually enlarged by rain. 



The faces of tracts of country are very much changed from time 



