2 DEFINITION OF THE TERM IXSECT- 



ters more closely — these vague and popular ideas are 

 insufficient. In common language, not only the tribes 

 above mentioned, but most small animals — as worms, 

 slugs, leeches, and many similar creatures, are known by 

 the name of insects. Such latitude, however, cannot be 

 admitted in a scientific view of the subject, in which the 

 class of insects is distinguished from these animals just as 

 strictly as beasts from birds, and birds from reptiles and 

 amphibia, and these again from fishes. Not, indeed, 

 that the just limits of the class have always been clearly 

 understood and marked out. Even when our corre- 

 spondence first commenced, animals were regarded as 

 belonging to it, which since their internal organization 

 has been more fully explained, are properly separated 

 from it But it is now agreed on all hands, that an 

 earthworm, a leech, or a slug, is not an insect; and a 

 Naturalist seems almost as much inclined to smile at 

 those who confound them, as Captain Cook at the island- 

 ers who confessed their entire ignorance of the nature of 

 cows and horses, but gave him to understand that they 

 knew his sheep and goats to be birds. 



You will better comprehend the subsequent definition 

 of the term Insect, after attending to a slight sketch of 

 the chief classifications of the animal kingdom, more es- 

 pecially of the creatures in question, that have been pro- 

 posed. That of Aristotle stands first. He divides ani- 

 iuals into two grand sections, corresponding with the Ver- 

 teC'rata and Invertebrata of modern Zoologists : those, 



namely, that have blood, and those that have it not a : 



i>y this it appears that he only regarded red blood as 

 red blood ; and probably did not suspect that there was 



1 Eu&ifiK, Avetiftct. Hist. Animal. 1. i. c. 6. 



