4 PREFACE TO THE FIRST EDITION. 
teresting, claimed to have the preference. Among the Invertehrata, I have had more 
particularly to study the naked mollusks and the great zoophytes ; but the innumerable 
variations of the external forms of shells and corals, the microscopic animals, and the 
other families which perform a less obvious office in the economy of nature, or whose 
organization affords but little room for the exercise of the scalpel, did not require to 
be treated with the same detail. Independently of which, so far as the shells and 
corals are concerned, I could depend on a work just published by M. de Lamarck, in 
which will be found all that the most ardent desire for information can require. 
With respect to insects, so interesting by their external forms, their organization, 
habits, and by their influence on all living nature, I have had the good fortune to find as- 
sistance which, in rendering my work infinitely more perfect than it could have been had 
it emanated solely from my pen, has, at the same time, greatly accelerated its publica- 
tion. My colleague and friend, M. Latreille, who has studied these animals more 
profoundly than any other man in Europe, has kindly consented to give, in a 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 which entomolo- 
gists are continually establishing. 
As for the rest, if in some instances I have given less extent to the exposition of 
sub-genera and species, this inequality has not occurred in aught that concerns the 
superior divisions and the indications of affinities, which I have every where founded on 
equally solid bases, established by equally assiduous researches. 
I have examined, one by one, all the species of which I could procure specimens ; I 
have approximated those which merely differed from each other in size, colour, or in 
the number of some less important parts, and have formed them into what I designate 
a sub-genus. 
Whenever it was possible, I have dissected at least one species of each sub-genus ; 
and if those be excepted to which the scalpel cannot be applied, there exists in my 
work but very few groups of this degree, of which I cannot produce some considerable 
portion of the organs. 
After having determined the names of the species which I had examined, and which 
had previously been either well figured or well described, I placed in the same sub- 
genera those which I had not seen, but whose exact figures, or descriptions, sufficiently 
precise to leave no doubt of their natural relations, I found in authors ; but I have 
passed over in silence that great number of vague indications, on which, in my opinion, 
naturalists have been too eager to establish species, the adoption of which has mainly 
contributed to introduce into the catalogue of beings, that confusion which deprives it 
of so much of its utility. 
I could have added, almost every where, a vast number of new species ; but as I 
could not refer to figures, it would have been incumbent on me to extend their descrip- 
tions beyond what space permitted : I have, therefore, preferred depriving my work of 
this ornament, and have only indicated those, the peculiar conformation of which gives 
rise to new sub-genera. 
My sub -genera once established on positive relations, and composed of well-authen- 
ticated species, it remained only to construct this great scaffolding of genera, tribes, 
families, orders, classes, and primary divisions, which constitute the entire animal 
kingdom. 
