INSECTS. 



89 



insect the abdomen may have thread-like (mole- 

 cricket) or pincer-like (earwig) appendages; or 

 appendages used in egg-laying (ovipositors, e.g. 

 Locust). 



Most insects have great powers of reproduction. A 

 few bring forth living young, but most insects lay 

 eggs. It is only in a few {e.g. lice) that animals 

 exactly like their parents are hatched from the eggs ; 

 the large majority of insects pass through a change, or 

 metatnorphosis. 



A distinction is drawn between complete and in- 

 complete metamorphosis. It is said to be complete 

 when the insect passes through a stage in which it 

 takes up no food, and, as a rule, moves but little. In 

 this condition of almost complete rest the insect is 

 called a "pupa" (Figs. 60, 61, 65). The metamor- 



FiG, 61. — The Hornet (^Vespa crdbro), with larva and pupa. 



phosis is called incomplete when the insect does not 

 pass through a pupa stage, and therefore feeds and 

 moves during all the periods of its development, 

 merely altering its form somewhat during its various 

 moults (Fig. 62). 



The word " moult " must here be explained. The 

 covering of the skin of Arthropods consists of hard 



