282 M. straus-durckheim's considerations. 



M. Stkaus-Durckheim's Arrangement of the Orders of Insecta. 



COLEOPTERA. 



No English naturalist, I believe, doubts that the Hymen- 

 optera are connected with the Coleoptera, consequently we 

 must remove them a little more to the left, and place them on 

 a level with the Neuroptera, with which order their affinity is 

 generally admitted. Few, moreover, will doubt the connexion 

 between Lepidoptera and Dipteru, and that of the former with 

 Hemiptera;— and what then? Why, we have the exact order 

 of the diagram, facing p. 21, in "Sphinx Vespiformis." The 

 Lepidoptera are undoubtedly allied to the Neuroptera; and 

 perhaps it would not be hard to prove an affinity between the 

 Neuroptera and Coleoptera , and between the former and some 

 Yioxao^ievom Hemiptera . At least here is enough to make us 

 consider a little before we reject a system which is in harmony 

 with so many natural affinities : for we must bear in mind that 

 that system is nearest to the natural system which exhibits the 

 greatest number of natural affinities, and breaks the fewest. 



Our author has placed Tabanus at the head of the Diptera; 

 but surely this is a desertion of his own principle, — " that it is 

 the less perfect species of any one great group which ap- 

 proaches nearest to the group which precedes or follows it." 



Perhaps a connexion may exist between the Hipnenoptera 

 and Diptera, by means of an insect which few would suspect. 

 In my copy of " Sphinx Vespiformis," the author has written 

 on the diagram, between these two orders, ^^PulexV Now of 

 this genus M. Straus has said, " Les puces quon pent con- 

 siderer coymne des Dipteres sans ailes," &c., thus allowing 

 an affinity to the Diptera, of course by Hippohosca. Recent 

 discoveries have, however, proved that the flea has distinct 



