XVI THE AUTHOR'S PREFACES. 



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 memor}', 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 

 Linnajus, but was necessaiy 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 emploj^ed 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 jirccisc 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 

 is. performed after the same manner ; and he who had cultivated this science merely 

 for amusqmeut, is surprised at the facilities it affords for disentangling all kinds of 

 affairs. 



It is not less useful in solitude. Sufficiently cxtens've 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 



