eti 



The Natural Order of Insects— Neuroptera. 



By \y. ]. Lucas, B.A., F.E.S. Read January 12///, 191 1. 



When, in the second half of the eighteenth centur}-, Linn^us, 

 by the pubHcation of his " Systema Naturpe," rescued the world of 

 Nature from the state of chaos which then existed, and drew up the 

 army of living things, known at the time, in ranks or " orders " 

 (natural ones as he intended them to be), one of the six devoted to 

 the insects was styled Neuroptera — the "nerve-winged." 



As every naturalist knows now, however, Nature does not lend 

 herself well to sharp divisions o-f this kind, as, indeed, might be 

 expected if the Theory of Evolution means anything at all. Con- 

 sequently, it is no way surprising that one of Linnjeus' natural 

 orders should perforce have to be a kind of omnhim gatherum of all 

 such insects as could not be easily classed — these constituted the 

 Neuroptera. ■ Not, of course, that Linnaeus necessarily looked 

 upon the matter in this light — but such is really the state of the 

 case ; and this being so, it is not surprising that there is a difficulty 

 in finding points in which all his Neuroptera agree, or, on the 

 other hand, such as will separate them satisfactorily from all 

 members of his other natural orders. In other words, it is barely 

 possible to frame a definition of the order Neuroptera i)i lata 

 sensii. Yet this state of things continued for a long time. 



Possibly, it was out of respect for Linnaeus that no change was 

 made ; or perhaps the difficulty involved in making a satisfactory 

 change prevented a change being made at all; or it may be that the 

 cause must be sought in the fact that these insects have been much 

 overlooked — by naturalists to a very considerable extent, and by 

 collectors to an even greater one. The Neuroptera constitute, in 

 fact, one of the so-called " neglected " orders. 



Subdivision of the Neuroptera had, of course, to be made by 

 those who were working at them : and at last the bolder spirits began 

 to carry further what had been partially done for some considerable 

 time — viz. to definitely split up this incongruous group of insects into 

 the orders of which it is naturally composed. I bhould say that the 

 Odonata (dragonflies) and Trichciptera (caddis-fiies) had often been 

 granted ordinate rank before the rest of the groups of the Neuroptera 

 had been considered worthy of such distinction. I do not intend, 

 however, to go fully into this matter, and shall refer to three schemes 

 of division onlv, all of fairly recent date. 



In 1885 Brauer proposed seventeen orders of insects, the 

 Neuroptera being divided into — 



