VIII 
CAUSES OF EXTINCTION 
183 
great collection lately brought to Europe from the caves of 
Brazil by MM. Lund and Clausen. In this collection there 
are extinct species of all the thirty-two genera, excepting four, 
of the terrestrial quadrupeds now inhabiting the provinces in 
which the caves occur ; and the extinct species are much more 
numerous than those now living: there are fossil ant-eaters, 
armadilloes, tapirs, peccaries, guanacos, opossums, and numerous 
South American gnawers and monkeys, and other animals. 
This wonderful relationship in the same continent between the 
dead and the living, will, I do not doubt, hereafter throw 
more light on the appearance of organic beings on our earth, 
and their disappearance from it, than any other class of 
facts. 
It is impossible to reflect on the changed state of the 
American continent without the deepest astonishment. Formerly 
it must have swarmed with great monsters : now we find mere 
pigmies, compared with the antecedent allied races. If Buffon 
had known of the gigantic sloth and armadillo-like animals, and 
of the lost Pachydermata, he might have said with a greater 
semblance of truth that the creative force in America had lost 
its power, rather than that it had never possessed great vigour. 
The greater number, if not all, of these extinct quadrupeds 
lived at a late period, and were the contemporaries of most of 
the existing sea-shells. Since they lived, no very great change 
in the form of the land can have taken place. What, then, 
has exterminated so many species and whole genera ? The 
mind at first is irresistibly hurried into the belief of some great 
catastrophe ; but thus to destroy animals, both large and small, 
in Southern Patagonia, in Brazil, on the Cordillera of Peru, in 
North America up to Behring’s Straits, we must shake the 
entire framework of the globe. An examination, moreover, of 
the geology of La Plata and Patagonia, leads to the belief that 
all the features of the land result from slow and gradual 
changes. It appears from the character of the fossils in Europe, 
Asia, Australia, and in North and South America, that those 
conditions which favour the life of the larger quadrupeds were 
lately coextensive with the world : what those conditions were, 
no one has yet even conjectured. It could hardly have been 
a change of temperature, which at about the same time destroyed 
the inhabitants of tropical, temperate, and arctic latitudes on 
