80 GROTE — SPECIALIZATIONS OF LEPIDOPTEROUS WING. [Jan. 21, 



taining the mass of holarctic forms of the *' Meadow Browns," the 

 lower branch of the media on the hind wings no longer fuses with 

 the cubitus, but, as in the Pieridae, springs from the cross-vein, the 

 piece between this branch and the cubitus varying in length, and by 

 so much marking here the grade of specialization. Except that vein 

 viii of primaries seems to have been entirely absorbed in the Aga- 

 petidae, it becomes difficult to distinguish their wings from the 

 Whites. In both groups the position of the radial branches is similar. 

 In the male sex the Agapetids show very frequently a bladder-like 

 swelling at the base of ii, iii and vii of primaries, or the swelling 

 may be confined more or less to the first-mentioned veins. In 

 Agapetes it seems confined to ii ; I do not find it in my preparations 

 of Oeneis aello, of which, however, I am uncertain as to the sex. 

 It is a secondary sexual specialization, of which traces occur also in 

 the Nymphalidae. Like the Pierids, the Meadow Browns tend to lose 

 vein i of secondaries by absorption ; I believe, on the whole, that 

 Pyronia represents the most specialized form. The amount of 

 fusion of ii and iii at base still continues greater as against the 

 Pieridae, but hardly holds its own in comparison with the Argyn- 

 ninas. In the Morphinae, which appear to me to be specialized 

 Agapetidae, the cell opens on hind wings, but remains closed on 

 primaries. They resemble thus the Pararginae at present rather than 

 the Agapetinae, and have sprung apparently from the latter. Else, 

 in our holarctic forms, the cell does not open on either wing, while 

 it becomes, in the specialized forms, partially degenerate. 



In the Heliconidae and Limnadidae the generalization makes 

 itself more and more evident. The strong veining, closed cells, 

 central position of ivo all tell against them. Heliconius still lacks 

 vein viii of primaries, but in Limnas it is stronger than in any 

 Pierid. At the close Libythea recovers somewhat of the lost terri- 

 tory, but this isolated butterfly, difficult to intercalate in a sequence, 

 cannot probably alter the average result. Taking this all in all, we 

 must find I believe that the excess of specialization in the direction 

 of the suppression of the media, and in the subsequent points here 

 explained, on the part of the brush-footed butterflies, as a whole, 

 cannot outweigh the absence of specialization by reduction of the 

 branches of the radius ; seeing also that only in one family, the 

 typical Nymphalids, is that specialization of the media carried to an 

 excess. We have also the difficulty of estimating the morphological 

 value of the shifting of vein ivi in the Pieridae. While we cannot 



