334 



THE WORLD OF ANIMAL LIFE 



should make the table interesting to us. In any case the table 

 will help us to classify the animals which we are about to discuss. 



INSECTS 



As we have seen in the preceding table, Insects are only a part 

 of the sub-kingdom Arthropoda, which includes spiders, scorpions, 

 centipedes, millipedes, crabs, and shrimps. 



Now the term " insect " (from Latin insectum, divided) originally 

 embraced all the groups of creatures which make up this sub- 

 kingdom. For all these animals are " divided " in the sense 



originally meant, and that was 

 that they were jointed animals, 

 some more and some less, but 

 all jointed in their bodies like a 

 lobster or a beetle. 



But true insects are distinct 

 from lobsters, and spiders, and 

 scorpions in many important 

 points; and so, when it was seen 

 that all the members of the great 

 group which are now known as 

 insects possess six, and only 

 six, legs, that was thought to be 

 a better mark of distinction; and 

 therefore the true insects are by 

 some now styled the Hexapoda 

 {i.e. the six-footed), which fact 

 we may at least bear in mind, as 

 the other groups in the Arthro- 

 poda are characterized by their members possessing more than six 

 legs. 



A further distinction of the true insects exists in the fact of 

 their bodies being divided into three easily-recognized portions, 



Diagram showing ihe parts of Insects 



«, Head ; h, chest ; c, abdomen ; dd, wing-cases ; 

 ee, wings: //, feelers. 



