562 INVESTIGATION OF INSECTS. 



authors, particularly Fabricius and Latreille, who have 

 subdivided the genera of Linne ; and you will see which 

 of your groups agree with theirs, detect your own errors, 

 and often theirs, and be enabled to label each of your 

 genera and higher groups, if already known, with its 

 modern appellation. You are now qualified also to 

 enter scientifically into the study of the characters that 

 distinguish groups, and may proceed, wherever oppor- 

 tunity is afforded, to examine the trophi, which may 

 often be displayed sufficiently by the means recommended 

 in my last letter a . In this way you may learn also to 

 know your groups as well by character as by habit, and 

 be qualified to trace the gradual progress of nature from 

 form to form; and may look upon yourself as duly pre- 

 pared to put the last hand to your labours, and proceed 

 to the examination of species. 



It will have occurred to you, in making out your genera 

 or lowest groups, that some consist of a vastly greater 

 number of species than others. It seems advisable 

 therefore, when you apply yourself seriously to ascertain 

 what described ones your cabinet contains, to begin with 

 those genera which appear to be poor in them ; for here 

 your labour will be comparatively light, from the small 

 number you will have to examine ; and you will become 

 practised in the employment before you are called upon 

 to attack those that overflow. Had Fabricius and 

 other describers of species taken the trouble to sub- 

 divide the larger groups, as might easily have been done, 

 into more genera and subge?iera, the student would have 

 been spared a most discouraging labour. To be obliged 



" See above, p. 546. 



