89 



are nearest Oleracea hyemalis 5 , but the nervures are blacker in 

 the former, and the costal margin of primaries is more extensively- 

 bordered black. Vcnosa ? , so far as I know it, has a second spot 

 not mentioned by Mr. Scudder, the one in sub-median interspace, 

 as seen in Napce. In this sex also my examples show no spot be- 

 7ieath on either iving, but all have a gray patch on upper side of 

 secondaries on costa. A large percentage of female Venosa are 

 yellow on upper side, another departure from the European type of 

 Napi. 



Comparing Vcnosa ^ with European examples of TVrt'/z (winter 

 form) sent me by Dr. Weismann, I find no tangible difference ex- 

 cept in the presence of the two spots on the under side of primaries 

 and the costal patch on secondaries, which is seen on all the Napi. 

 All the Napi have one spot on primaries above, either distinct 

 and black, or a cluster of black scales, and all have a patch on 

 secondaries on both sides. These differences seem to be per- 

 sistent, and indicate a departure in the American type. The 

 females of the two forms differ also by the presence of the tzuo spots 

 beneath {Napi), or in their total absence {Venosa^. 



Venosa is the winter form in British Columbia, Vancouver's 

 Island, Oregon, Washington Territory and California, and in all 

 that region it is followed in its second generation by the summer 

 form Pallida, Scudder. In the middle of the continent and to the 

 eastward another winter form has replaced Venosa, viz. ; 

 Oleracea hyemalis. But not absolutely, for I have from Quebec a 

 2 not differing in any particular from Venosa $ of Vancouver's 

 Island. But this occasional appearance is probably owing to re- 

 version. 



Dr. Boisduval, Lep. de la Cal., p. 38, says of Nasturtii $ , de- 

 scribed as a Californian species : " Is this Pieris an American modi- 

 fication of our European species or a variety of Oleracea ? It re- 

 sembles much our Napi, from which it does not greatly differ, 

 except that beneath the ground is less yellow, with the nervules 

 more largely dilated .... and finally because tJie two black 

 spots of the upper side do not appear beloivy This \s Venosa $ , re- 

 sembling Napi, as I have before said, except in wanting these 

 spots. 



3. Oleracea. The primary form throughout the polar re- 

 gions of both continents being Bryonies, in the next generation 

 there has come to be a divergence, some characters being present 

 in the European [Napi) which are not found (or rarely if at all) 

 in the American {Vcnosa), as I have shown above. But further, 

 the American has developed a second distinct zvinter form, viz. : 

 Oleracea hyemalis, originating apparently with the immaculate 

 males of Vcnosa. That Oleracea was considered by Dr. Boisdu- 

 val as peculiar to America is evident from his description, Spec. 

 Gen. I, p. 518: "-Oleracea: Upper side absolutely as in our 

 Napi, but zvithout any black mark, so that the four zvings are wholly 



