AN INSECT. 



Definition. — The term "insect" is popularly and 

 wrongly given to almost any small animal such 

 as spiders, scorpions, centipedes, etc. Briefly, an 

 insect is an animal whose body is divided into 3 

 parts (i) head, (2) thorax, (3) abdomen, and which 

 has 3 pairs of legs attached to the thorax. (Plate 

 I, Fig. i). 



Classification. — The Animal Kingdom is divided 

 irto several great divisions called Sub-Kingdoms or 

 phyla. The Sub-Kingdom or phylum to which in- 

 sects belong is the Arthropoda or animals with 

 jointed appendages. This includes forms with a 

 body having ring-like parts. They differ from 

 the Phylum Annulata (worms) in having distinct 

 limb segments. 



The Phylum Arthropoda is divided into 5 classes : 



I. Crustacea: Crabs, lobsters, shrimps. 



II. Arachnida: Spiders, scorpions, ticks, mites. 



III. Insecta: Insects such as flies, bees, crickets, 

 beetles, etc. 



IV. Myriapoda: Centipedes and millipedes. 



V. Onychophora: Peripatus. 



We may now state (with more detail) that an 

 insect is a small animal, having a body made up of 

 a number of ringed parts, slightly horny, being 

 grouped in three distinct regions, known as (a) the 



