290 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1934 



a single species sometimes differ not only in adjacent valleys, but 

 sometimes also in different portions of the same valley, or on differ- 

 ent sides of the same peak. 



Probably all of the butterflies of the far north, and many of the 

 alpine types as well, require 2 years, some possibly longer, in which 

 to complete their transformations. Yet a few of the parnassians 

 living high in the Himalayas in northern India have two broods a 

 year. 



As a rule, arctic and alpine butterflies are smaller than their rela- 

 tives farther south or in the valleys, and are also dingier or darker 

 in color, at least on the under side. Their bodies and heads are 

 very hairy. 



THE BUTTERFLIES OF SPRING 



Spring begins in earnest in the vicinity of Washington, D. C, 

 about the middle of March. The conspicuous white flowers of the 

 bloodroot appear in the woods above the carpet of fallen leaves. 

 The leafy rosettes of the dandelions, the thistles, and the milfoil, 

 bright green and fresh, are of good size, and the clovers, grasses, 

 daisies, and other low-growing plants have put forth many bright 

 green leaves. The trees as yet are leafless, but the elms, willows, 

 alders, spice-bush, and some others are in flower. The cardinals, 

 song-sparrows, robins, white-throated sparrows, mourning doves, and 

 all of the smaller frogs are in full song, and the flickers and the 

 phoebes are heard on all sides. Turtles are appearing on the logs 

 and mud banks, reveling in the stimulation of the bright sunlight 

 after the darkness of their long hibernation. At this time or some- 

 what later in April, no less than 34 different kinds of butterflies are 

 to be found upon the wing. These 34 species are divisible into four 

 groups. 



The largest group includes 16 species all confined to North Amer- 

 ica, but ranging widely throughout the continent. All of them live 

 far to the northward, though only one, the yellow swallowtail {Pap- 

 ilio glaucud) passes the Arctic Circle. All of these have at least 

 two broods a year. 



The next largest group includes eight southern species, about half 

 of which range southward into the Tropics. The most interesting in 

 this group are the blue swallowtail {Papillo philenor), the zebra 

 swallowtail (P. marcellus) , and the orange-tip {Anthocaris genutia). 

 In this group falls the most brilliantly colored of all the local butter- 

 flies, the lovely azure hair-streak {Stnjinon tii-alhum). All but the 

 orange-tip have at least two broods a year. The last has only a single 

 brood in the vicinity of Washington, flying from March to early 

 May ; but in the cooler mountain regions farther south there are two 



