18 SCHOOL ENTOMOLOGY 



Light-producing or luminescent insects have special 

 structures for the production of light which are not well 

 understood. The light is thought to be the result of a 

 very finely developed process of oxidation whereby prac- 

 tically all the energy from the oxidation is made into light 

 instead of into heat. These structures are closely con- 

 nected with the respiratory system. 



External projections from the skeleton are frequent and 

 do not usually appear to serve any useful purpose. They 

 may be either ornamental or merely vestiges of structures 

 that were, formerly, of use to the species. 



