TIME DIVISIONS OF THE ICE AGE. 407 
present a record of climatic changes south of the glaciated 
area, by which geologists may very satisfactorily connect 
the evidences of primitive man in France with the time 
divisions of the Glacial period. His detailed notes of each 
of the three Pleistocene series and stages recognizable in 
these valleys are fully quoted by Professor James Geikie 
in the third edition of the Great Ice Age (1894, pp. 630-632), 
from which it appears that flint implements of the Acheulian 
or Chellean type occur throughout the lower series; that 
such implements are also found in the middle series, but 
probably, as Ladriére thinks, through derivation from the 
older and_ stratigraphically lower beds; and that the 
infrequent implements found in the upper series are of 
the later developed Mousterian type. 
We may infer, additionally, that while the still later 
Solutrian and Magdalenian types of implements were 
being developed, in the progress of the Paleolithic 
period, more moderate climatic conditions prevailed in 
northern France, with no important contribution to the 
valley gravels. These threefold deposits therefore appear 
referable to three distinct parts of the Ice age, probably 
the Albertan, Kansan, and Iowan stages of glacial advance, 
or rather to the European representatives of these 
stages. During the interval that ensued, previous to the 
Champlain subsidence and general recession of the ice-sheet, 
the Paleolithic men of western Europe passed through their 
Solutrian and Magdalenian stages; and shortly afterward, 
about the time of formation of the Wisconsin or Mecklenburg 
moraines, those men, destitute of metals, of agriculture, or 
of domestic animals, were practically crowded off from 
Europe, famished by extinction of the large species of 
game, and driven out, exterminated, or absorbed, by the 
immigrating Neolithic people. The wvaders, though 
ignorant cf the most useful metals, brought wheat and 
barley, cattle, sheep, goats, and swine, and, most significant 
in linking them with later written history, the Indo-European 
or Aryan languages. Their arrival and settlement, and the 
end of the Paleolithic period, preceded the departure of the 
ice-sheet from Scotland and Scandinavia, where no Paleeo- 
lithic types of stone implements are found, although Neolithic 
types abound and are collected in immense numbers. 
Sections of the Somme gravels at Menchecourt, Mautort, 
and other localities near and below Abbeville carry back the 
Acheulian stage of Paleolithic time quite to the beginning 
