142 Notes on the G-eological Position of the Human 
gives a presumption rather than a proof of a certain age, 
inasmuch as such association is largely dependent on negative 
evidence for any weight it may possess, and negative evidence 
is always liable to be more or less upset by new discoveries. 
The result of the drainage of the Lake of Haarlem gives a 
hint on this point. It was drained about thirty years ago; 
excellent sections were made in all directions across its bed, 
and carefully examined by skilled geologists. As many 
Dutchmen and Spaniards had perished in its waters three 
centuries ago, and it had always been the centre of a 
considerable population, plenty of human bones were expected. 
Yet none were found, the only remains of man being some 
wrecked Spanish vessels and a few coins; though the bones 
of men buried on battle-fields are not more decayed than 
those of horses interred with them. Thus, Mammalia un¬ 
equal to the production of works of art might easily leave no 
signs of their former existence in a deposit in which hundreds 
or even thousands of them had been buried. (See Lyell’s 
Antiq. Man, ed. iii., p. 147). 
Thus, had extinct Mammalia and flint implements of the 
most primitive type been found associated with the Tilbury 
skeleton, no one would have been thereby more justified than 
now in calling the skeleton Palaeolithic. For their presence 
in Recent strata could only show their extinction to be of 
more modern date than had previously been supposed, and 
could confer no additional antiquity on the beds themselves. 
Similarly, the rude and savage character of the Tilbury or 
any other skeleton can in itself give no presumption of 
Palaeolithic rather than Neolithic age. No doubt, on the 
average, men of the rude Neanderthal type were decidedly 
commoner among the makers of the rude, or Palaeolithic, 
implements than among the users of polished, or Neolithic, 
tools. But many Neanderthal-like men may have used 
polished implements, there being no inseparable connection 
between highly-finished implements and elegantly-shaped 
skulls. 
In short, when terms like Palaeolithic and Neolithic are 
used, on the one hand, in the provisional classification of 
