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long cherished opinions, from the fact that in no science has 
such extraordinary revelations taken place within the last 
half century as in geology. I cannot forget that, less than 
forty years ago, it was considered heresy to suppose that any 
animal remains higher in the scale than the Mollusca were to 
be found beneath the Lias. When no Mammalian remains 
were allowed to occur lower than the Upper Tertiary, or 
Calcaire Grossier, and when the Quadrumana, or Monkeys, 
were not even supposed to have been called into existence ! 
What, however, is now the fact? Not only have above two 
hundred species of fishes been found in the various strata 
extending down to and even in the Old Red Sandstone, but 
Reptilian remains also have been satisfactorily demonstrated 
in the Coal itself. The Marsupialia have been detected in 
the Stonesfield slate, and Monkeys, as large as any now 
existing, in the Eocene formations. Surely then, such 
revelations as these, in direct opposition to supposed 
fundamental doctrines, ought to teach us the useful, 
though humiliating lesson, that it is wiser to withhold judg- 
ment than to draw too rigidly the exact line or period when 
certain animals ceased to exist, and also, whether Man was 
or was not also their associate. For, in the elegant lansruaore 
of Sir C. Lyell, I would observe, — The recent progress of 
discovery in our science puts us upon our guard against 
founding hasty generalisations on mere negative evidence, 
and warns us against the presumption of taking for granted 
that our present knowledge of the earliest occurrence of a 
particular class of fossils in stratified rocks can be reasoned 
upon as if it afforded a true indication of the first appearance 
of a particular class of beings on the globe.* 
Finally, then, in my endeavour to trace the Megaceros down 
to the human era, I am by no means advocating the idea that 
they have, as species, been equally long inhabitants of this 
* Address to the Geological Society, February, 1850. 
