COLIAS IV. 



submitted to Mr. Edwards and lie now concedes the polymorpliism of this spe- 

 cies. 



The summing up of these histories in the several districts is as follows : — 



I. In northern Colorado, where the summer is short, the species is but digo- 

 neutic, the butterflies of the tirst brood appearing in June, and the second in 

 July and August. Probably the species is here preserved by the survival of 

 some of the last butterflies, which hybernate and deposit their eggs in spring. 

 It is doubtful if the climatic conditions will permit the growth of larvte late in 

 the season and their consequent hybernation. The species is restricted to Kee- 

 waydin and intergrades up to the paler variety of Eurytheme, but a few individ- 

 uals are taken which show a tendency to vary in the direction o^ Ariadne. (Var. 

 B. Fig. 6.) If there be any hybernating larvae they would probably produce 

 these individuals spoken of. 



II. In Illinois and Nebraska the species is trigoneutic, and many of the ear- 

 liest brood are nearer Ariadne than Kcewaydln, but the typical Ariadne does 

 not appear. Some individuals of the last brood of butterflies survive the winter, 

 and thus appear in early spring in company with the butterflies that have come 

 from hybernating larva^, and consequently must breed with these. Aiad inter- 

 grades between the forms are the result, and such are to be found throughout 

 the year. So that in Illinois and Nebraska, as in Colorado and probably through- 

 out the northern range of the species, it is rather a varialjle than a poljmor- 

 phic species, and either form or any variety of either may appear from any one 

 laying of eggs. 



III. In California, in the lowlands, the species is polj^goneutic, either three or 

 four Ijrooded, tlie earliest brood, which flies in February and March, being 

 Ariadne. Keeioaydin forms the second Ijrood, which flies in April, and this 

 form is on the wing during the remainder of the season. Eurytheme appears m 

 July, and is abundant in August and September. And Ariadne appears in 

 localities at different periods throughout the summer, and apparently in such 

 localities must form part of every brood. Keeioaydin is the usual form through- 

 out the season in the mountains and also in Oregon and on Vancouver's Island, 

 Eurytheme being rare. And Ariadne is taken occasionally also in those districts. 

 By which it appears that in the lowlands of California there is a strong disposi- 

 tion towards polymorpliism as distinguished from mere variableness, all the 

 forms being present, and, moreover, that each in great degree is limited in its 

 season. The surface of California is extremely varied, lofty mountains alternat- 

 ing with narrow valleys, with corresponding differences of climate. Near San 

 Francisco frost and snow are unknown, and there is every degree of climatic 

 difference between this and a sub-boreal climate in one part or other of that 



