XX PREFACE TO THE FIRST EDITION. 
of animals, in which I should give their divisions and sub-divisions in 
the greatest detail, as established both in their internal and external 
structure; in which I should indicate the best authenticated species be- 
longing to each of the subdivisions, and in which, to increase the interest, 
| should add some details regarding those species that are rendered re- 
markable by their being so common in this country, by their utility or 
mischievous practices, by the singularity of their habits and their economy, 
by their strange forms, their beauty, or their size. 
In so doing I hoped to prove useful to young naturalists, who, for the 
most part, have but little idea of the confusion and errors of criticism in 
which the most accredited works abound, and who, in foreign countries 
particularly, do not sufficiently attend to the study of the true relations of 
the conformation of beings; I considered myself as rendering a more 
direct service to those anatomists, who require to know beforehand to 
what orders they should direct their researches, when they wish to solve 
any problem of human anatomy or physiology by comparative anatomy, 
but whose ordinary occupations do not sufficiently prepare them for ful- 
filling this condition, which is essential to their success. 
I had no intention, however, of extending this two-fold view to all the 
classes of the animal kingdom; and the Vertebrated animals, as in every 
sense the most interesting, naturally claimed a preference. Among the 
Invertebrata, I had to study more particularly the naked Mollusca and 
the great Zoophytes; but the innumerable variations of the external forms 
of shells and corals, the microscopic animals, and the other families whose 
part, on the great theatre of nature, is not very apparent, or whose or- 
ganization affords but little room for the use of the scalpel, did not require 
a similar minuteness of detail. Independently of this, so far as the shells 
and corals were concerned, I could depend on the work of M. de Lamarck, 
in which will be found all that the most ardent thirst for knowledge can 
desire. 
As regards Insects, which, by their external form, organization, habits, 
and influence on all animated nature, are so highly interesting, I have 
been fortunate enough to find assistance, which, in rendering my work 
infinitely more perfect than it could have possibly been had it emanated 
from my pen alone, has, at the same time, considerably accelerated its 
publication. My friend and colleague, M. Latreille, who has studied 
these animals more profoundly than any other man in Europe, has kindly 
consented to give, ina single volume, and nearly in the order adopted for 
the other parts, a summary of his immense researches, and an abridged 
description of those innumerable genera entomologists are continually es- 
tablishing. 
With respect to the remaining portion, if I have given in some places 
