INTRODUCTORY OBSERVATIONS. 3 
dulge conjecture ; but when we attempt to penetrate the 
darkness of primitive ages, and pretend to trace the 
first causes of such things, we wander in regions from 
which human knowledge is excluded. He alone, that 
great First Cause, ‘ by whom all things were made 
that are made,” is alone master of this impenetrable 
secret. 
(3.) Let us now look to the animal world. Here we 
may see thousands of beings, endowed with powers of 
locomotion which have been utterly denied to man. 
The swallow, darting like an arrow through the air at 
the rate of sixty miles an hour, seems to mock the com- 
paratively snail-like pace of our swiftest vessels ; the 
curlew runs rapidly on the ground, mounts on the 
breaking surge, or swiftly flies from one continent to 
another, thus traversing, with perfect ease, three ele- 
ments, — the earth, the air, and the sea. Thousands, 
in short, of little tiny birds perform journies, every 
spring and autumn, any one of which, to us, would be 
the occupation of a year. Now the theoretical conclusion 
we should make, on considering these facts, would be, 
that animals, so peculiarly gifted with the powers of 
locomotion, would use it to wander in every clime, 
that they would spread their races in every region of 
the earth where food could be procured, or where they 
could enjoy a fit temperature. These deductions, 
theoretically, cannot be deemed otherwise than just. 
Yet they are diametrically opposed and contradicted by 
facts. The swallow of England might reach America 
or China in as short a space of time as it would travel 
to Africa, and in either country would find food and 
warmth congenial to its nature ; but it has been ap- 
pointed to pursue a certain course; and from that course, 
whether to the right or to the left, it never deviates. 
This is only one out of a thousand instances, to prove 
that the limits of every animal have been fixed by 
an Almighty fiat —“ Hither shalt thou come, but no 
further.” Man may do much with those animals which 
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