THE ANTIQUITY OF MAN AND THE ORIGIN OF SPECIES. 633: 
(a) Early Pleistocene, in which the European land was more elevated and ex- 
tensive than at present (First Continental Period of Lyell), and in which Europe: 
was colonized by animals suitable to a temperate climate. No good evidence of 
the presence of man. 
(6) Atid Pletstocene. In this period there was a great extension of cold climate 
and glaciers over Europe, and mammals of arctic species began to replace those 
previously existing. There was alsoa great subsidence of the land, finally reducing 
Europe toa group of islands in a cold sea, often ice-laden. Two flint flakes found. 
in brick earth at Crayford and Erith in England are the only known evidences of. 
man at this period. 
(c) Late Pleistocene. The land was again elevated, so that Great Britain and: 
Ireland were united to each other and to the continent (Second Continental Period. 
of Lyell). The ice and cold diminished. Modern land animals largely predomi- 
nate, though there are several species now extinct. Undoubted evidences of man, 
of the so-called ‘‘ Paleolithic race,” ‘‘ Riverdrift and Cave men,” ‘‘Men of the 
Mammoth and Reindeer periods.” 
II. Preuistoric Periop: In which domestic animals and cultivated fruits. 
appear; the land of Europe shrinks to its present dimensions. Man abounds, and 
is similar to races still extant in Europe. Men of ‘‘Neolithic age,” ‘‘ Bronze 
age,” ‘‘ Prehistoric Irgn age.” 
Ill. Hisroric Periop: In which events are recorded in history. 
I have given this classification fully, in order to point out in the first place- 
certain serious defects in its latter portion, and in the second place what it actually 
shows as to the appearance of man in Europe. 
In point of logical arrangement, and especially of geological classification, 
the two last periods are decidedly objectionable. Even in Europe the historic age: 
of the south is altogether a different thing from that of the north, and to speak of 
the prehistoric period in Greece and in Britain or Norway as indicating the same 
portion of time is altogether illusory. Hence a large portion of the discussion of 
this subject has to be called by our author ‘‘the overlap of history.” Further, the- 
mere accident of the presence or absence of historical documents cannot constitute 
a geological period comparable with such periods as the Pleistocene and Pliocene, 
and the assumption of such a criterion of time merely confuses our ideas. On the one: 
hand, while the whole Tertiary or Kainozoic, up to the present day, is one great 
geological period, characterized by a continuous though gradually changing fauna: 
and series of physical conditions, and there is consequently no good basis for set-- 
ting apart, as some geologists do, a Quarternary as distinct from the Tertiary 
period; on the other hand there is a distinct physical break between the Pleisto- 
cene andthe Modern in the great glacial age. ‘This in its arctic climate and 
enormous submergence of the land, though it did not exterminate the fauna of 
the Northern Hemisphere, greatly reduced it, and at the close of this age many 
new forms came in. For this reason the division should be made not where- 
Dawkins makes it, but at or about the end of his ‘‘ Mid Pleistocene.” The natur- 
al division would thus be: 
I, PLEISTOCENE, including— 
(2) Early Pleistocene, or First Continental period. Land very extensive,. 
moderate climate. 
