Dec. iS97] GROTE: CLASSIFICATION OF LePIDOPTERA. 155 



have called the "moving veins" appear to follow a still active law of 

 development. Of the three primary veins, Radius, Cubitus and 

 Media, the two main trunks have attained a certain fixity opposi- 

 tion through processes which have been carried on during an unmeasur- 

 able past. The criticism which our knowledge of the direction of the 

 venation allows us of the recently published systems of classification is : 

 that these are often founded on characters the relative value of which 

 has not been ascertained, their recurring nature not taken into account. 

 It is as though I had placed Nemeobius among the Pieridae, because its 

 pattern of venation demanded it, and then proceeded to erect a violent 

 system upon such a basis after the fashion of Mr. Meyrick. But much 

 better work will be done in working out all the variations in a single 

 organ, endeavoring to bring out clearly the value of these variations 

 and allowing the existing classificatory sequence, I might say the Lm- 

 iiean sequence, as a rule, to stand. The work before us is still to make 

 what is now difficult, easy. When we have reached this goal upon any 

 point of our subject, there will arise plenty to take up the matter and 

 display their penetration upon it further. 



So we see that the principal gain from these studies is the attainment 

 of a measure, a distinct register, of specialization. By it the groups and 

 genera drop more naturally into their places. And these studies are 

 critical of Mr. Meyrick's pretensions, who would arrange the Lepidop- 

 tera upon neuration but offers us a mass of incorrect figures, an impos- 

 sible phylogeny and the proof positive that he has nowhere understood 

 the movement of the veins. So, too, they reach classificators who 

 blindly thrust the Swallowtails between the Blues and Hesperids, and 

 they show that these also, have not even understood the conditions of 

 the problem they assume to have solved with so much pomp of learning. 



In Comstock's "Evolution and Taxonomy," to which work my in- 

 debtedness is very great, I find no distinct recognition of the two main di- 

 rections of evolution in the wings as such, while there is everywhere ap- 

 parent the laudable effort to correlate the changes with mechanical causes. 

 The suppression of the Media is detailed on page 76. In this, my first 

 direction, the movement of IV2 is thus discussed : " But in which 

 direction would one expect the base of vein V2 to migrate ? Occupying 

 an intermediate position between radius and cubitus it may go either 

 way. It is like a stream in the middle of a level plain, a trifle may 

 change its course." The view taken by me is that there is a contest be- 

 tween Radius and Cubitus for the possession of the residue of the 

 Media, after base and crossvein have degenerated. The two principal 



