ON 



THE HISTORY 



AND 



NATURAL ARRANGEMENT 



OF 



INSECTS. 



PART I. 



ON THE ANNULOSA GENERALLY. 



CHAPTER I. 



N THE ANNULOSE ANIMALS IN GENERAL, WITH A SHORT AC- 

 COUNT OF THE THREE ABERRANT CLASSES OF ANNELIDES 

 VERMES, AND CIRRHIPEDES. 



(1.) TL HE great characteristic of the vast assemblage of 

 animals to which we devote this volume, is the total 

 absence of internal bones : hence their hardest parts are 

 always external, and the muscles are usually attached 

 to the under side of the substance which forms the 

 covering of the animal. The body is always divided 

 into rings or transverse joints ; from which circum-" 

 stance naturalists have agreed to call them annulose, 

 or ringed animals. This name is peculiarly applicable, 

 since it expresses a marked distinction from such as 

 have an internal skeleton, analogous to that of man, 

 and thence called vertebrate {yertebrata). We need 

 not, in this place, touch further upon the internal 

 structure of these creatures ; but we shall notice those 

 external peculiarities which are most obvious, and there- 

 fore most likely to be understood by the generality of 

 our readers. So diversified, indeed, are the different 



