INSECTS. 



II 



CASE 

 I. 



INSECTS-Generalities. 



The general arrangement adopted in this work is the fol- 

 lowing : — 



1. Aptera, or Wingless Insects 



(Spiders, Mites, Lice, &c.) 



2. Hemiptera, or Bugs. 



3. Orthoptera (Earwigs, Cock- 



roaches, Locusts, &c.) 



4. Diptera, or Two-winged flies. 



5. Hymenoptera (Eees, Wasps, 



&c.) 



6. Neuroptera (Dragonflies). 



7. Lepidoptera (Butterflies and 



Moths.) 



8. Coleoptera (Beetles). 



At the commencement it may be proper to note the following 

 generalities, for the benefit of those to whom the subject is new. 

 Insects, in their most complete character, pass through four 

 stages or phases of existence — the ^gg^ the larva (maggot or 

 caterpillar) stage, the chrysalis, and the perfect stage. In none 

 of these, except the larval or caterpillar stage, does the insect 

 increase in size. It is not unusual to hear people speak of a 

 small beetle or moth being the young of a larger one that is 

 otherwise like it, but after insects have come out of the chrysalis 

 stage they never grow — all the growth is done in the earlier stage 

 when they are caterpillars. If we sometimes meet with two 

 insects of the same species but of different size, the difference is 

 due to the supply of food which the caterpillar had during its 

 growth, and is only a parallel case to an ill-nourished child growing 

 up into a stunted man. Some insects, as the Aptera, pass only 

 through three stages : the egg, the younger state, and the perfect 

 form — and some of the intermediate orders also attain perfection 

 without passing through more than two. 



The egg is usually deposited, but in some few cases it is hatched 

 in the body of the parent ; in some others it is, at one period 

 of the year, deposited as an egg, and at another the progeny is 

 brought forth alive. In others again it is sometimes the one and 

 sometimes the other. In the larval stage the insect casts its skin 



