REVIEW — THE NATURALIST’S LIBRARY. 
703 
thatFerol horses that had once been reclaimed and made tame, but 
which from circumstances had again become wild, had in their future 
progeny assumed a form and character approaching to the original 
wild breed, one would suppose that these facts alone would be suf- 
ficient to prove that the horse had a claim to a pure original form- 
ation, as much as man himself. 
An interesting paper was read some time since by M. Roulin 
to the Academy of Science at Paris, on the changes which the 
domestic animals undergo when transported to the equatorial re- 
gions of the new world. The hog, in the warm valleys of South 
America, wandering in the woods and subsisting upon wild fruits, 
becomes ferocious and assumes almost the character of the wild 
boar. In St. Domingo and New Grenada the cow undergoes a 
material change. Jt no longer furnishes the supply of milk which 
we obtain from it in Europe ; for when the calf ceases to suck, the 
milk immediately dries up. Lastly, the horses multiplied in such 
an extraordinary degree shortly after the first settlement of the 
Spaniards that it required the united testimony of the aboriginals 
and the evidence of the terror they at first excited to establish the 
absolute credibility of their having been imported. These animals, 
as well as the pig and ox, have become wild, having entirely lost 
all marks of domesticity, and have in some measure reverted to the 
original characters of their species. 
In dogs also we have excellent examples of the reversion to an 
original breed. In Cuba, Hayti, and in all the Caribbean Islands, 
they have become wild. “ In the course of the seventeenth cen- 
tury,” says Lyell, “ they hunted in packs, and fearlessly attacked 
herds of wild boars and other animals.” It is natural to inquire to 
what form they reverted ? They are said by many travellers to 
have resembled very nearly the shepherd’s dog; but it is certain 
that they were never turned into wolves. 
These facts alone appear to me sufficient evidence to prove that 
the horse has from the creation existed as a pure, unmixed, and ori- 
ginal animal; and it really does seem more rational to suppose that 
the powerful agencies of habit, food, climate, and domestication 
had been the cause of the different varieties, than to resort to the 
opinion that such varieties had been originally formed as were 
adapted to the spots whereon they have been placed. Every per- 
son who knows any thing of the history of animals must admit that 
great changes do take place in them from the long action of these 
causes. To these influences we must attribute the diversified ap- 
pearance of the ox species. We have a singular but striking 
example of this in the different varieties dispersed over our own 
islands, where almost every district or county has its peculiar 
breed, which are generally distinguished by the name of the par- 
