SPECULATIVE THEORIES ANSWERED. 9 
be said to prove the fallacy of this hypothesis ; for al- 
though it is utterly impossible to trace the origin of our 
domestic breeds to one or more original stocks, since even 
the species cannot now be distinguished from the vari- 
eties, still the whole tenor of zoological facts is totally 
against this belief. The plains of the new world, no 
less than those of Australia, are as perfectly adapted for 
the comfortable existence of the horse or the ox, as are 
the fields and the pastures of Europe, or the grassy 
deserts of Asia; yet nature has placed these animals in 
one hemisphere, and denied them to the other. 
(11.) Some other writers might be mentioned, who, 
in attempting to explain the causes of animal distribu- 
tion, have either been but little acquainted with well 
known zoological facts, or have been led into theories too 
wild and fanciful to deserve notice. We may, indeed, 
build a theory upon every thing in nature: but the more 
we investigate, the stronger will be our conviction in the 
following deduction :—That the primary causes which 
have led to different regions of the earth being peopled 
by different races of animals, and the laws by which 
their dispersion is regulated, must be for ever hid 
from human research. This conclusion is strengthened 
by the inference which will be drawn from the facts we 
shall subsequently state ; an inference so well expressed 
by a very intelligent writer, that we shall give it nearly 
in his own words. “ It appears that the various tribes 
of organised beings were originally placed by the Creator 
in certain regions, for which they are by their nature 
peculiarly adapted. Each species may have had only 
one beginning in a single stock ; probably a single pair, 
as Linneus supposed, was first called into being, and 
their progeny left to disperse themselves to as great a 
distance from the original centre of their existence as 
was compatible with its physical capabilities, and with 
those unknown laws, by which the Creator has regulated 
the geographic distribution of his creatures.” 
(12.) We have now endeavoured to demonstrate the 
insufficiency of all theories on the causes of animal dis= 
