iv OTHER SEASON- VARIETIES 123 



There are still other butterflies known which have a 

 summer and a winter form which were formerly believed to 

 be distinct species, e.g. the two blue forms, very different in 

 marking and in size, Lycsena Polysperchon and L. Amyntas, 

 as shown by P. C. Zeller l by rearing experiments ; further, 

 the white forms belonging to the Mediterranean shores, An- 

 thocharis Belia and A. Ausonia, as shown by Dr. Staudinger. 2 



Weismann speaks of five such species. But there are 

 more whose winter and summer forms were formerly described, 

 not as species, but as varieties. Weismann mentions twelve. 

 Among these are several of our commonest white butter- 

 flies, and also the commonest of our blue species, Lycsena 

 Alexis, in which the differences between winter and summer 

 form are very small. I may add that the sail -butterfly 

 (Papilio Podalirius) forms a southern darker variety, P. Feist- 

 hamelii Dup. (South Europe, North Africa, West Asia), and 

 that this produces in Algiers a second peculiarly marked 

 generation, the P. Letteri, Const. 



The American butterfly Papilio Ajax wherever it occurs 

 appears in three varieties, viz. var. Telamonides, Walshii, 

 and Marcellus. The American entomologist Edwards has 

 shown by breeding experiments that all three belong to one 

 cycle of development, and that Telamonides and Walshii 

 emerge only in spring, while Marcellus occurs only in summer, 

 and in three successive generations. Marcellus is therefore 

 the form produced by summer, that is, by warmth. Tela- 

 monides and Walshii, according to Weismann, are to be 

 regarded as the ancestral forms. Of these Telamonides is 

 considered to be due to " imperfect reversion," like Porima, 

 Walshii as the original form of the species. Edwards records 

 that out of fifty pupse of the second summer generation of 



1 Stett. entomolog. Zeitsch. 1849. 



2 Ibid. 1862 : " The Species of the Lepidopterous genus Ino, with Remarks on 

 Local Varieties." 



