THE STUDY OF ENTOMOLOGY 227 



the individuals he has collected should be classified. 

 For further identification the student must refer to the 

 following chapters of this part which treat of the 

 generic and specific differences which will enable him 

 to determine these points. 1 also propose to treat 

 briefly of the larval, nymphal, and pupal stages of the 

 various insects, so that the fisherman who wants to 

 dive more deeply into the subject can obtain some 

 notion of the nature of the immature insects he will 

 find when collecting below the surface with the 

 digging-net. 



