INTKODUCTION TO ENTOMOLOGY. 17 



The second portion (called the thorax, or sometimes 

 the "trunk") is formed of three rings, bearing a pair of 

 legs attached to each, and having usually a pair of wings 

 on the second and third of the rings ; but sometimes the 

 wings are wanting, sometimes there is only one pair. 



The third portion (called the abdomen) is formed of the 

 remaining nine rings, and contains the organs of repro- 

 duction and most of those of digestion. 



Insects in this perfect state are of two sexes, male and 

 female; in some instances (as with wasps and some 

 others) there are imperfectly-developed females, known as 

 "neuters." 



After the insect — whether beetle, butterfly, fly, or other 

 kind — has come forth from its chrysalis or fly-case (that 

 is from the pupa), and its limbs have expanded, it grows 

 no more ; it is complete, and its remaining work is to 

 support life until it has propagated its species. Usually 

 pairing soon takes place, and the male dies; but the 

 female has great tenacity of life until she has laid her 

 eggs. The length of life, however, is various; in some 

 instances a few days, or even hours, is the extent; in 

 others the insects " hybernate," that is, find some shelter 

 in which they pass the winter, and from which they re- 

 appear with the return of warmth and sunshine. 



