174 CAUSES OF EXTINCTION. [Cuar. VIIL 
sistibly hurried into the belief of some great catastrophe; but 
thus to destroy animals, both large and small, in Southern Pata- 
gonia, 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 fromslow 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 /arger quadrupeds were lately co-extensive with 
the world: what those conditions were, no one has yet even 
conjectured. It could hardly have been a change of tempera- 
ture, which at about the same time destroyed the inhabitants of 
tropical, temperate, and arctic latitudes on both sides of the 
globe. In North America we positively know from Mr. Lyell, 
that the large quadrupeds lived subsequently to that period, when 
boulders were brought into latitudes at which icebergs now never 
arrive: from conclusive but indirect reasons we may feel sure, 
that in the southern hemisphere the Macrauchenia, also, lived 
long subsequently to the ice-transporting boulder-period. Did 
man, after his first inroad into South America, destroy, as has 
been suggested, the unwieldy Megatherium and the other Eden- 
tata? We must at least look to some other cause for the destruc- 
tion of the little tucutuco at Bahia Blanca, and.of the many 
fossil mice and other small quadrupeds in Brazil. No one 
will imagine that a drought, even far severer than those which 
cause such losses in the provinces of .La Plata, could destroy 
every individual of every species from Southern Patagonia to 
Behring’s Straits. What shall we say of the extinction of the 
horse? Did those plains fail of pasture, which have since been 
overrun by thousands and hundreds of thousands of the descend- 
ants of the stock introduced by the Spaniards? Have the subse- 
quently introduced species consumed the food of the great ante- 
cedent races? Can we believe that the Capybara has taken the 
food of the Toxodon, the Guanaco of the Macrauchenia, the ex- 
isting small Edentata of their numerous gigantic prototypes? 
Certainly, no fact in the long history of the world is so startling 
as the wide and repeated exterminations of its inhabitants. 
Novertheless, if we consider the subject under another point of 
