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 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 Edentata?
We must at least look to some other cause for the destruction of the little tucutuco at Bahia Blanca, and of the many fossil mice and other small quadrupeds in Brazil.