HABITS AND STRUCTURE OF INSECTS. 85 



With few exceptions worms live in the water, and even 

 those which live on the land are limited to damp earth or 

 moist places. While the larvse of insects are in many cases 

 aquatic in their habits, and breathe or respire by means of 

 gills, the larger number live on the land, feeding on leaves, 

 wood, and substances of a similar nature, and are air- 

 breathers. 



CHAPTER XL 



HABITS AND STRUCTURE OF INSECTS. 



81. LET the pupils now endeavor to study the habits of 

 certain insects by direct observation. The following sketches 

 are given as aids to the pupils in making independent obser- 

 vations on special insects. 



Most insects make no provision for the larvse, but leave 

 them to take care of themselves, though usually the egg is 

 deposited where the larva coming from it may find proper 

 food at hand. 



Other insects prepare cells or cavities in which they de- 

 posit their eggs, just as a bird builds a nest to hold its eggs. 

 Certain insects, in preparing these cells, also lay up a store of 

 food ready for the larva when it shall have hatched from the 

 egg. Such is the case with the common mud-wasp. This 

 insect makes a number of little chambers of mud, generally 

 sticking them to the sides of a wall, or to the ceilings of sheds, 

 barns, and attics. These pellets of mud are seen firmly plas- 



