( clxvii ) 



bably separated, and that the present more or less simpler 

 development has been evolved therefrom. Those families, 

 popularly called the lower or the older groups, have all of them 

 rather complex organs, with evidences of vestiges of a separated 

 anus ; as development progressed, its progression should be 

 towards simplicity, for it is hard to persuade oneself that gi'eat 

 complexity in these parts is for the benefit of the race, the 

 simpler and the more effective the better for the species ; in 

 most of the Heterocera there are signs in this direction. If 

 we consider the Rhopalocera it is much more in evidence, 

 but perhaps it is most interesting to find that one of the oldest 

 families has quite the simplest armatm'e ; I refer to the 

 Ruralidae or Lycaenidae, where the armature and the aedoeagus 

 are, generally speaking, of the simplest pattern I know of, 

 taking the whole family into consideration, among all the 

 Lepidoptera, and perhaps next to them come the Erycinidae. 

 I am unable to speak with authority on such orders as the 

 Diptera and the H5^menoptera, but in both of these orders, 

 where long and sustained flights are the habits generally 

 obtaining, we must be prepared for deviation from the standard 

 of the Lepidoptera ; in both groups we find the armature 

 complex and powerful. 



Each order must be worked out on its own lines, the economy 

 of the insects necessarily affecting their structure to some 

 extent. It may be that those who are not well acquainted 

 with this line of study will find it difficult at first to fully 

 comprehend all the structures, this can be, however, remedied 

 by any one who desires to investigate the subject ; the initial 

 difficulties are by no means great, all that is required is 

 patience and a more or less delicate touch, with these and good 

 eyes any one can overcome the difficulty of technique in the 

 preparation of the necessary microscopic slides. This being 

 accomplished the field of research is great, and I believe is 

 destined to become of the utmost importance in the near 

 future. 



Perhaps I should say a word on the best position for ob- 

 servation of these organs. Without any doubt at all the 

 natui-al position should be taken, and in the Lepidoptera, the 

 Trichoptera and the Neuroptera that is the profile view ; in 



