32 
INTRODUCTION. 
The earth, -which had been to man a sealed book, was open- 
ed, and, read by the light of the new philosophy, disclosed 
the history of its own creation. The order of events, 
in the production and succession of animal life upon its 
surface, began to be understood. The relations of 
different beings to each other were studied, and all 
were seen to be mutually dependent. Order and sys- 
tem were thus substituted for confusion, and philosophi- 
cal zoology became one of the prominent subjects which 
claimed the attention of the speculative and the learned. 
The active interest in this science, originating in 
France, gradually extended to such parts of the conti- 
nent of Europe a.s were influenced by the French 
language and literature, or were occupied by her armies, 
which were often attended by commissions of scientific 
men, and sometimes numbered, among their officers, 
naturalists of the highest merit. In England, when in 
consequence of the wars growing out of the French 
Revolution, and continuing until the dethronement of 
Napoleon, a state of non-intercourse with France existed, 
the new impulse was not felt until a later date. "When 
it was received, however, it produced a decided impres- 
sion, and was soon followed by a rapid advance in tins 
department of knowledge. Its results have been the 
training of a numerous body of scientific naturalists, 
among whom are some of the most distinguished men of 
the present age. 
At the period first alluded to, the United States, then 
not long emerged from colonial subjection, was engaged 
