1898.] GHOTE — SPECIALIZATION'S OF LEPIDOPTEROUS WING. 2^ 



even when we descend to the '' Fritillaries," where the cell of fore 

 wings closes and vein ivj becomes quite central, the superiority 

 is kept up. For everywhere on the hind wings of the Nymphalidoe 

 does the lowest branch of the media, vein iv,,, completely fuse with 

 the cubitus. The cross-vein above it is always very weak, and 

 even vanishes in Araschnia, Melitcea or Euptoieta. 



Leaving the two principal directions in which the movable veins 

 show the effects of specialization, we can compare the Pieridae and 

 Nymphalidce upon other points. The most important of these is 

 the fusion of ii and iii upon the hind wings at base. Here the 

 Nymphalidas continue their advantage. In the Nymphalinae the 

 absorption extends even to the point of issuance of i, and this mea- 

 sure is attained in the most specialized of the Agapetid?e or 

 " Meadow Browns," the Pararginae. In the mass of the Nympha- 

 lidas this excess is not reached and the point of absorption falls 

 varyingly short. But still it is always carried to a further point 

 than in the PieridjE, where the union is very brief and apparently 

 quite wanting in Leptidia. This character is plainly secondary and 

 cannot of itself determine the phylogeny. Again, the amount of ab- 

 sorption of i may be compared, a vein which is relatively constant in 

 its position upon ii, from which it issues. It did not always probably 

 do so, for I have observed in Papilio, Zerynthia (=:Thais) and Par- 

 nassius, the process by which it has come to be fused with ii, and in 

 the present group traces of its independence may be found in the 

 Limnads or " Milk Weed " butterflies. In the Pieridae this vein i, 

 the so-called ^'praecostal spur," tends to be absorbed and disap- 

 pears in Eurymus (Colias) and Colias (Gonepteryx). Here the 

 parallelism in specialization with the ''Blues" is continued. But in 

 the Nymphalid?e it appears everywhere to be strong and well-de- 

 veloped ; it is here more generalized. Evidently the strong flight 

 continued to call for a strengthening of the shoulder of the secondary 

 wings. In the fiutterings of the ''Whites," the "Meadow 

 Browns," the "Blues," this need was not so felt and the vein 

 would tend to disappear. 



So much we may say in comparing the Pieridae with the Nym- 

 phalidce proper, and we may pass more quickly over our comparisons 

 of the " Whites " with the remaining families of " brush-footed " 

 butterflies, the " Nymphalidse " of Scudder and Comstock. After 

 we leave the Pararginae, the scale of specialization comes to a stand- 

 still or turns gradually against the latter. In the Agapetinse, con- 



