NORTH AND SOUTH. 373 



and old pastures and along the borders of the streams. The sweet 

 gum or bilsted, with its gray- colored branches winged with corky 

 ridges, its spiny autumn fruit, and its five-starred leaves, fragrant 

 when crushed and turning crimson in the fall, is a characteristic 

 tree of this borderland. Curiously enough, too, it is confined to 

 the lowlands, growing quite abundantly in the moist woods along 

 the Delaware just south of Philadelphia, but unknown in the 

 northern suburbs save as a transplanted tree. 



These woodland features give a decided southern tinge to the 

 region, and are especially significant when we come to know that 

 the tulip tree belongs with the magnolias, a typical southern 

 group, and that the persimmon is one of the ebony trees, a family 

 characteristic of the tropics. But it is the presence of a Caro- 

 linian element in the fauna, especially the bird fauna, that marks 

 this region as the beginning of the southern realm. At all sea- 

 sons of the year the clear whistle of the Virginia redbird the 

 crested cardinal with mask of black may be heard in the woods 

 of the lower Delaware Valley and along the tributary streams. I 

 have seen its flash of red against the whiteness of midwinter snow- 

 drifts. In the bramble thickets that fringe the streams and on 

 the wooded slopes above, the Carolina wren finds a home the year 

 round, and its clear, ringing song breaks loudly on the frosty 

 stillness of late winter mornings. I know of no more character- 

 istic sounds in these woods in the early springtime than this 

 wren's song and that of the tufted titmouse. It is a noteworthy 

 fact that these three Carolinian birds are resident throughout the 

 year along the northern limit of the fauna. When the spicebush 

 has blossomed, and " all the wood stands in a mist of green," the 

 first bird waves of the spring tide of migration appear. We wake 

 some morning to hear the chipping sparrow striking pebbles 

 together, and catch the plaintive song of the field sparrow in the 

 pastures and the budding copses along the edge of spring woods. 

 Only yesterday these sounds of the spring were but a memory. 

 The thrasher pours out a medley of sweet notes from the high 

 tree top, and later, in the warm days of early May, the reedy, 

 mellow lute of the wood thrush comes from the bosky glade. 

 During the migration the voices of birds sound unceasingly 

 through the woods from dawn to twilight. When the blackberry 

 is white with blossoms and the arrowwood is in bloom, most of 

 the migrants have passed on to their northern breeding grounds, 

 and those that stay with us have built their nests. Among these 

 latter are several Carolinian birds. In the depths of smilax and 

 brier-tangled thickets the skulking chat the wildest bird of the 

 woodland utters its weird, delusive cries. The low-pitched, in- 

 sectlike notes of the blue-winged warbler and the song of the 

 worm- eating warbler that sounds like a chipping sparrow in the 



