BUTTERFLIES OF THE DISTRICT OF COLUMBIA 83 



escape is a sight that may be witnessed a hundred times a day wher- 

 ever these butterflies and these locusts are common. 



Frequently the buckeye will turn from its course and follow grass- 

 hopper and Henslow's sparrows {Ammodramus savannarum aus- 

 tralis and Passerherbulus henslowi sussurans) that fly up from the 

 grass. But it is not swift enough to catch up with them, and they 

 seem to pay no attention to it. 



Late in summer barren spaces in hillside fields where male buck- 

 eyes congregate are kept almost completely free of other species by 

 their aggressive actions. 



Notes. — The local variation in this butterfly, elsewhere remark- 

 able for the extent and diversity of its aberrations, is sur- 

 prisingly slight. Occasional individuals are met with in which the 

 light band on the fore wings is entirely obliterated, being replaced 

 by brown, and the eye spots and other markings are rendered more 

 or less indefinite by an admixture of brown scales. Slight irregu- 

 larities in the form of the eye spots, especially the development 

 of an angle on one side of the eye spot on the fore wing, are frequent. 

 There is some variation in the relative size of the posterior eye 

 spot on the hind wing, though this is never much reduced. 



A specimen in the National Museum taken by S. D. Nixon at 

 Baltimore, Md., has the spots on the upper surface of the hind 

 wings enlarged and confluent. 



/Seasons. — In the District the buckeye has three broods a year. 

 The first brood, composed of relatively few individuals, appears in 

 the first week of June, the numbers slowly increasing and reaching a 

 maximum in the last half of June and early in July. The second 

 brood appears toward the end of July while worn individuals of the 

 first brood are still on the wing, and extends well into August. The 

 third brood appears during the last week in August, and the butter- 

 flies of this brood increase in numbers until after the middle of Sep- 

 tember. The butterflies of the second brood are more numerous than 

 those of the first, and those of the third are much more numerous than 

 those of the second, being in some years very abundant. The butter- 

 flies of the third brood are seen sunning themselves on warm days 

 late in October, occasionally in November, and rarely early in De- 

 cember, in which month I have noticed them on the parking space at 

 the western end of the New National Museum building. These butter- 

 flies hibernate, but only a very few of them, all of the dry form with 

 no pink on the underside of the hind wings, survive the winter. The 

 few survivors reappear in the first half of May when ragged individ- 

 uals may occasionally be seen on the flower beds in the Department 

 of Agriculture grounds and elsewhere ; they disappear early in June. 



