PREFACE TO THE FIRST EDITION. ea 
Encouraged by these reflections, 1 determined to precede 
my treatise on comparative anatomy by a kind of abridged 
system of animals, in which I would present their divisions 
and subdivisions of all degrees, established in a parallel man- 
ner upon their structure, external and internal ; where I would 
give the indication of well ascertained species, which certainly 
belong to each of the subdivisions, and where, to create more 
interest, I would enter into some details upon such of those 
species, which from their abounding in our country, the uses 
to which we put them, the evils they cause us, the singularity 
of their habits and economy, their extraordinary forms, their 
beauty or their size, become the most remarkable. 
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 con- 
formation of beings; I considered myself as rendering a more 
direct service to those anatomists, who require to know be- 
forehand 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 oc- 
cupations do not sufliciently prepare them for fulfilling 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 organization affords but little 
room for the use of the scalpel, did not require a similar mi- 
nuteness of detail. Independently of this, so far as the shells 
and corals were concerned, I could depend on the work of 
