from Oviedo, were not uncommon,
and there were even some that amounted to eight thousand. In 1587, the
number of hides exported from St. Domingo alone, according to Acosta's
report, was 35,444; and in the same year there were exported 64,350 from
the ports of New Spain. This was in the sixty-fifth year after the
taking of Mexico, previous to which event the Spaniards, who came into
that country, had not been able to engage in anything else than
war.[979] Every one is aware that these animals are now established
throughout the American continent from Canada to the Straits of
Magellan.

The ass has thriven very generally in the New World; and we learn from
Ulloa, that in Quito they ran wild, and multiplied in amazing numbers,
so as to become a nuisance. They grazed together in herds, and when
attacked defended themselves with their mouths. If a horse happened to
stray into the places where they fed, they all fell upon him, and did
not cease biting and kicking till they left him dead.[980]

The first hogs were carried to America by Columbus, and established in
the Island of St. Domingo the year following its discovery, in November,
1493. In succeeding years they were introduced into other places where
the Spaniards settled; and, in the space of half a century, they were
found established in the New World, from the latitude of 25 degrees
north, to the 40th degree of south latitude. Sheep, also, and goats have
multiplied enormously in the New World, as have also the cat and the
rat; which last, as before stated, has been imported unintentionally in
ships. The dogs introduced by man which have at different periods become
wild in America, hunted in packs, like the wolf and the jackall,
destroying not only hogs, but the calves and foals of the wild cattle
and horses.

Ulloa in his voyage, and Buffon on the authority of old writers, relate
a fact which illustrates very clearly the principle before explained, of
the check which the increase of one animal necessarily offers to that of
another. The Spaniards had introduced goats into the Island of Juan
Fernandez, where they became so prolific as to furnish the pirates who
infested those seas with provisions. In order to cut off this resource
from the buccaneers, a number of dogs were turned loose into the island;
and so numerous did they become in their turn, that they destroyed the
goats in every accessible part, after which the number of the wild dogs
again decreased.[981]