[9] COLLECTING AND PRESERVING INSECTS RILEY. 



connection. Authors have differed in the past and will diner in the 

 future as to what constitutes a natural system, and it would require 

 many pages to give even a brief survey of the various schemes that 

 have been proposed. As I have elsewhere said, "We must remember 

 that classifications are but a means to an end appliances to facilitate 

 our thought and study and that, to use Spencer's words, -we cannot, 

 by any logical dichotomies, actually express relations which in nature 

 graduate into each other insensibly.' ' 



The most philosophical, perhaps, of the more modern systems of clas- 

 sification is that of Fried rich Brauer, who has carefully studied the 

 subject, and has given us an arrangement consisting of sixteen orders. 

 This has many merits and has been adopted, with slight modifications, 

 by Packard in his " Entomology for Beginners," and by Hyatt and 

 Arms in their recent and valuable text-book "Insecta." Cornstock, 

 in his "Introduction to Entomology" strongly recommends Brauer's 

 classification, but for reasons of simplicity and convenience adheres to 

 a modification of the old classification of West wood. 



For purposes of comparison the classification by Hyatt and Arms, 

 which is substantially that of Brauer, may be introduced. 



In linear arrangement it is as follows: 



I. Thysauura (Springtails, etc.). 

 II. Ephemeroptera (Ephemeridw; May-flies). (=Plectopte>'aP&ck.) 



III. Odouata (Libellulidce; Dragon-flies). 



IV. Plecoptera (Perlidw; Stone-flies). 



V. Platypter'a (Termites, Mallopltaga, etc.). 

 VI. Dermaptera (Forficulidte; Earwigs). 

 VII. Orthoptera (Locusts, Grasshoppers, etc.). 

 VIII. Thysauoptera (Thripidce; Fringe- wings). 

 IX. Hemiptera (Bugs). 

 X. Coleoptera (Beetles). 



XI. Neuroptera (Sialidw, Hemerobiidce; Lace-wings, etc.). 

 XII. Mecoptera (Panorpidw; Scorpion-flies). 



XIII. Trichoptera (Phryganeidce; Caddis-flies). 



XIV. Lepidoptera (Butterflies and Moths). 

 XV. Hymenoptera (Bees, Wasps, etc.). 



XVI. Diptera (Two-winged flies). 



The relationship of these orders cannot be indicated in a linear 

 arrangement, and is admirably shown by Hyatt and Arms by means of 

 diagrams which I reproduce (Figs. 2, 3.) 



