I06 SMITHSONIAN INSTITUTION 



almost entirely deep orange which in the males has a heautiful violet 

 iridescence. These last represent a wet form of the species, the 

 kecivaydin type is intermediate, and the small yellow individuals ( form 

 ariadnc) represent the dry form. 



In the District the driest season is in the late summer and the wettest 

 in the spring. So in this region the various types of this unusually 

 interesting hutterfly are curiously mixed. The earliest individuals are 

 of the hrilliant orange form, which is the last to appear in Texas. 

 This persists throughout the season, and in boggy pastures near the 

 river reaches an immense size. In the middle of July the intermediate 

 form (kcczcaydiii) begins to become common, tlying with the other. 

 In late summer the small yellow form with a slight flush of orange is 

 also to be found, in compan\- with the other two. Here we have an 

 example of a butterfly in a new region adapting itself to varying 

 conditions within a restricted area by the production of forms which 

 elsewhere have a seasonal significance, after the fashion of the buck- 

 eye (Jimonia ca^na). 



In a region permanently or seasonally wet, vegetation is everywhere 

 luxuriant, while in a region permanently or seasonally dry, growing 

 plants are relatively few and widely scattered. In correlation with 

 this, the dry forms of our local butterflies are as a rule much more 

 active than the wet. They have longer fore wings and are more 

 inclined to wander. As a concrete illustration I may mention the differ- 

 ence in the habits of the hop merchant {Polygonia comma) and the 

 question mark {Polygonia interrogationis) in summer and in autumn. 



The dark, short-winged summer individuals are mostly found in 

 deciduous woods, especially along wood roads, in open glades, and 

 along the borders of wooded districts. While shy and active, they 

 seldom stray far from their place of origin. 



The light, long-winged autumn individuals are at first found in 

 deciduous woods, flying with worn examples of the dark parent form. 

 But later they largely desert the woods and become widely dispersed 

 throughout the open countr}', where the}- are especially to be found 

 along the roads, the bare earth of which is warmed by the sun of the 

 cool autumn days. When startled these light-colored individuals fly 

 away and seldom return to the place they left. 



Pressure of population among the butterflies gives rise to the ap- 

 pearance of phenomena also seen in man under similar conditions. 

 Perhaps the commonest of these phenomena is haphazard wandering. 

 Many butterflies in early spring when the individuals are few in 

 number must be sought for in their proper habitats, to which they are 



