6 PREFACE TO THE FIRST EDITION. 
so very repulsive. I cannot perceive, however, that I have thereby lost any thing in 
precision or clearness. 
I have been compelled, unfortunately, to introduce many new names, although I 
have endeavoured, as far as possible, to preserve those of my predecessors ; but the 
numerous sub-genera I have established required these denominations ; for in things 
so various, the memory is not satisfied with numerical indications. I have selected 
them, so as either to convey some character, or among the common names which I 
have latinized, or lastly, after the example of Linnaeus, from among those of mytho- 
logy, which are generally agreeable to the ear, and which we are far from having 
exhausted. 
In naming species, however, I would nevertheless recommend employing the sub- 
stantive of the genus, and the trivial name only. The names of the sub-genera are 
designed merely as a relief to the memory, when we would indicate these sub- 
divisions in particular. Otherwise, as the sub-genera, already very numerous, will in 
the end become greatly multiplied, in consequence of having substantives continually 
to retain, we shall be in danger of losing the advantages of that binary nomenclature 
so happily imagined by Linnaeus. 
It is the better to preserve it that I have dismembered as little as possible the great 
genera of that illustrious reformer of science. Whenever the sub-genera into which 
I divide them were not to be translated into different families, I have left them together 
under their former generic appellation. This was not only due to the memory of 
Linnaeus, but was necessary in order to preserve the mutual intelligence of the 
naturalists of different countries. 
To facilitate still more the study of this work, — for it is to be studied more than to be 
glanced over, — I have employed different- sized types in the printing of it, to correspond 
to the different grades of generalization of the statements contained in it. * * * 
Thus the eye will distinguish beforehand the relative importance of each group, and the 
order of each successive idea ; and the printer will second the author with every con- 
trivance which his art supplies, that may conduce to assist the memory. 
The habit, necessarily acquired in the study of natural history, of mentally classify- 
ing a great number of ideas, is one of the advantages of this science, which is seldom 
spoken of, and which, when it shall have been generally introduced into the system of 
common education, will perhaps become the principal one : it exercises, the student in 
that part of logic which is termed method, as the study of geometry does in that 
which is called syllogism^ because natural history is the science which requires the 
most precise methods, as geometry is that which demands the most rigorous reason- 
ing. Now this art of method, when once well acquired, may be applied with infinite 
advantage to studies the most foreign to natural history. Every discussion which sup- 
poses a classification of facts, every research which requires a distribution of matters, i 
is performed after the same manner ; and he who had cultivated this science merely 
for amusement, is surprised at the facilities it affords for disentanghng all kinds of i 
affairs. i 
It is not less useful in solitude. Sufficiently extensive to satisfy the most powerful | 
mind, sufficiently various and interesting to calm the most agitated soul, it consoles | 
the unhappy, and tends to allay enmity and hatred. Once elevated to the contem- 
plation of that harmony of Nature irresistibly regulated by Providence, how weak and 
