Notices respecting Neio Books. 551 



which the great flutings and projecting cornices of rock show how 

 the eroding action of weather has taken advantage of the relative 

 hardness of the limestone bands. These beds are very nearly hori- 

 zontal, but dip slightly towards the north-west ; and the irregular 

 action of the weathering or destroying agent has therefore pro- 

 duced at many places, both at high and low levels, caves and rock 

 shelters in which the ancient dwellers of the valley lived. Thus 

 the cave at Les Eyzies is 100 feet above the river-level, and Le 

 Moustier 90 feet, while others again are but little above the level 

 of the extraordinary inundations of the Vezere, though now, owing 

 to the accumulation of a talus of limestone debris, the entrances 

 are often completely hidden, as in the Cro-Magnon cave, the dis- 

 covery of which was accidentally made during the construction of 

 a railway approach. 



The excavations and discoveries were made at six places : at 

 Laugerie Haute, Laugerie Basse, Le Moustier, Gorge d'Enfer, 

 and La Madelaine were rock shelters ; at Le Moustier, Les Eyzies, 

 Gorge d'Enfer, and Cro-Magnon were caves; and in all these 

 numerous relics of human occupation and quantities of mammalian 

 and other bones were found buried and concealed, sometimes under 

 successive layers of stalagmite, sometimes under masses of earth 

 and detritus, resulting from the destruction of the rocky roof of 

 these ancient dwellings. 



The method whereby these hollows thus became places of bone- 

 deposit had been long a subject for conjecture. Some attributed 

 it to the action of wild beasts who made these caves their lairs ; 

 others deemed the action of torrent-water washing down the re- 

 mains of animals and filling these hollows a sufficient cause ; but 

 that Man has had more to do with this infilling of the cave-stuff is 

 fully proved by the evidences of human work and art in the relics 

 he left behind. The first suggestion, that they were Hyaena-lairs, 

 may be dismissed at once, as no gnawed bones were found among 

 the debris ; and this probably further indicates that the ancient in- 

 habitants had some means of closing the entrances against such 

 intruders. 



The relics described and pictured are chiefly of stone, bone, and 

 antler, with some of ivory, and a few shells and other ornaments. 

 The particular prehistoric age or horizon to which these may be 

 referred can be more or less easily determined. There are three 

 great periods into which prehistoric time is usually divided : — the 

 surface-period, where implements are found associated with tombs 

 and places of sepulture ; and here the relative age of each lies within 

 the province of the archaeologist. The Cave-period, previous to 

 the construction of regular habitations for the living or tombs for 

 the dead, offers with the implements only bones of animals whereby 

 the palaeontologist can estimate their antiquity. Then the drift- 

 period carries us further back still in time ; and here the ruder 

 implements are rarely definitely associated with bones, there are 

 no other human relics to guide us, and the determination of their 

 age therefore rests only with the geologist : many of the older 



