The various layers indicate that the cavern was successively occupied by man; in or near the hearths are found stone implements, broken and incinerated bones, and pieces of charcoal, which may indicate that this grotto was visited only at intervals, perhaps during the colder seasons of the year. (=1=) Harlé, 1910.1. (=2=) d'Ault du Mesnil, 1896.1, pp. 284-296. (=3=) Obermaier, 1912.1, p. 146. (=4=) Schmidt, 1912.1, pp. 118-126. (=5=) Boule, 1888.1. (=6=) Obermaier, 1912.1, pp. 327-329. (=7=) Haug, 1907.1, vol. II, pp. 327-329. (=8=) Geikie, 1914.1, p. 262. (=9=) Morlot, 1854.1. (=10=) Commont, 1906.1. (=11=) Geikie, 1914.1, pp. 107-111. (=12=) d'Ault du Mesnil, _op. cit._ (=13=) Schmidt, 1912.1, pp. 124, 125. (=14=) Obermaier, 1912.1, p. 118. (=15=) Dawson, 1913.1; 1913.2; 1913.3. (=16=) Kennard, 1913.1. (=17=) Reid, 1913.1. (=18=) Dawson, 1913.1, p. 123; 1914.1, pp. 82-86. (=19=) Keith, A., 1913.1; 1913.2; 1913.3. (=20=) Smith, G. E., 1913.1; 1913.2; 1913.3; 1913.4. (=21=) Boule, 1913.1, pp. 245, 246. (=22=) Schwalbe, 1914.1, p. 603. (=23=) Osborn, 1910.1, pp. 404-409. (=24=) Ewart, 1904.1; 1907.1; 1909.1. (=25=) Obermaier, 1912.1, p. 120. (=26=) de Mortillet, 1869.1. (=27=) Obermaier, _op. cit._, p. 116. (=28=) Lyell, 1863.1, p. 164. (=29=) Geikie, 1914.1, pp. 119, 263, 264. (=30=) Schmidt, 1912.1, pp. 125, 126. (=31=) Geikie, _op. cit._, p. 228. (=32=) Avebury, 1913.1, p. 342, Fig. 236. (=33=) Schmidt, _op. cit._, pp. 17-105. (=34=) Breuil, 1912.5, p. 14. (=35=) Obermaier, 1912.1, p. 164. (=36=) Obermaier, _op. cit._, pp. 124, 125, 127, 130. (=37=) Commont, 1908.1. (=38=) Déchelette, 1908.1, vol. I, pp. 80-90. (=39=) Geikie, 1914.1, p. 255. (=40=) Hilzheimer, 1913.1, p. 145. (=41=) Obermaier, 1912.1, p. 127. (=42=) Fischer, 1913.1. (=43=) Gorjanovič-Kramberger, 1901.1; 1903.1; 1906.1. (=44=) Schwalbe, 1914.1, p. 597. CHAPTER III CLOSE OF THE THIRD INTERGLACIAL, TEMPERATE, AND ARID CLIMATE, ACHEULEAN INDUSTRY--ADVENT OF THE FOURTH GLACIATION, PROFOUND CHANGES IN ANIMAL AND PLANT LIFE--THE ARCTIC TUNDRA PERIOD OF MAMMALIAN AND PLANT LIFE--CHARACTERS OF THE NEANDERTHAL RACE, OF THEIR MOUSTERIAN FLINT INDUSTRY--SUPPOSED CAUSES OF EXTINCTION OR DISPERSAL We now reach a prolonged and important stage in the prehistory of Europe, namely, the period of the fourth glaciation, of the final development of the Neanderthal race of man, of the Mousterian industry, of the beginnings of cave life, of the chase of the reindeer, and its use for food and clothing. In all Europe the Acheulean industry appears to have come to a close during a period of arid climate, warm in some parts of western Europe and cool or even cold in others. The seasonal variations may well have been extreme, as on the steppes of southern Russia, where exceedingly hot summers may be followed by intensely cold winters, with high winds and snow-storms destructive of life.