DISTINGUISHING CHARACTERS OF INSECTS. 15 



are in their nature and construction farther removed 

 from the birds than these are from the lion and the tiger ; 

 nay, that that which is the apparent link between these 

 " fowls" (to use the inclusive term of an old writer), 

 namely, the power of flight, is attained by organs which 

 are absolutely without any relation but that of their 

 function ; and which consequently form no true link as 

 regards the structure and constitution of the two animals, 

 the bird and the insect. 



The object then of the present chapter is to show the 

 characters by which insects are distinguished from 

 animals of other classes. To do this it will be necessary 

 to lay before the reader a slight sketch of some of the 

 leading characters of both one and the other. 



Throughout the animal kingdom we find several plans, 

 as it were, or systems; even as the animal kingdom itself 

 is one system among many others in creation. It appears 

 as if the Creator had confined within these plans or 

 systems such variations of detail as were essential to 

 attain all the ends which He had in view, and what these 

 ends were we may in a great measure ascertain by the 

 study of nature herself, learning from this the work which 

 is done, and the variety of life and enjoyment with which 

 our world is filled, by the multiplication of living beings 

 under a diversity of form, habit, and character. 



The whole of the animal kingdom is divided by science 

 into two great classes, namely, the Vertebrata, or animals 

 possessing a spinal column, and the Invertebrata, or 

 animals which are without this. It must be noted, however, 

 that while the class Invertebrata contains many systems or 

 groups, as those of the insects, the worms, the " shellfish," 

 and others, Vertebrata contains but a single such system 

 or group, within which are only such differences as are 



