16 POPULAR ENTOMOLOGY. 



orders are retained, though considered unnecessary by other 

 entomologists of equal celebrity ; these may be easily dis- 

 missed by those students who gain sufficient experience 

 from the works of Nature and the study of science to be 

 enabled to form their own opinion ; while to the mere ama- 

 teur it is of little importance, and certainly unadvisable, to 

 enter into questions which the learned cannot satisfactorily 

 set at rest. 



Insects constitute the fifth class in the third sub-kingdom 

 of animated nature. Some authors make two great divi- 

 sions, Ametabola, insects undergoing no metamorphosis, 

 and Metabola y those which undergo the three great changes 

 from larva to pupa, and thence to the imago or perfect in- 

 sect ; but the latter of these divisions only will be consi- 

 dered, as the former consists of insects little interesting to 

 a beginner in the science, and indeed their situation is 

 much disputed by entomologists. They consist of THYSA- 

 NAURA, divided into two small families, Lepismidce and 

 Poduridce, minute insects without wings, found under stones, 

 and floating on water ; and ANOPLURA, also divided into 

 two families, Pediculidce and Nirmidw, these consist of 

 the parasitic insects which are found living on animals and 

 birds, known by the general name of Lice. 



