PREFACE TO THE FIRST EDITION. XI 



Encouraged by these reflections, I determined to precede 

 my treatise on comparative anatomy by a kind of abridged 

 system of animals, in vvhicii I would present their divisions 

 and subdivisions of all degrees, established in a parallel man- 

 ner upon tlieir stracture, 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 thenij 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, 

 vyho, 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 sufficiently 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 Vertebra ted 

 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 



