OF ARTS AND SCIENCES. 57 



waterfowl and shore birds pursue a somewhat similar course, 

 and on reaching our large lakes and rivers often stop to feed or 

 rest. 



A number of special cases might be mentioned as of interest. 

 Thus, as stated elsewhere, there seems to be a more or less well 

 defined migration of Brunnich's Murres across the lower part of 

 the state in late fall, many birds seeming to make a cross cut 

 from the Maine coast to the Connecticut valley. Certain north- 

 ern warblers, as the Tennessee, Cape May, Bay-breasted and 

 Mourning Warblers, seem to pass over the southern part of the 

 state in their spring flight, and are rarely seen there though 

 common in the White Mountains or to the north of them in 

 summer. The fall migration of the Black-poll Warblers (Den- 

 droica striata} is of more than usual interest as observed among 

 the White Mountains. These birds breed commonly in the 

 balsam forests of the upper Canadian zone mainly above 3,000 

 feet on southern exposures, and down to 2,000 feet on the north- 

 ern slopes. During September they swarm, in migration, over 

 the low country of the southern part of the state and beyond, 

 but in the valley bottoms among the mountains are usually un- 

 common, if not rather rare. Here they migrate mainly at the 

 upper levels and along the mountain tops. Thus at Intervale, 

 a careful search in the lower valleys and woods from the Saco 

 up to some 1,500 feet on the neighboring mountains will fre- 

 quently fail to discover more than a scattered individual or two 

 among the flocks of other small warblors and chickadees, but 

 higher up along the tops of the lower mountains they are fair- 

 ly common. Thus, on September 10, 1900, I went up Mts. 

 Bartlett and Kearsarge (northern), the latter 3,260 feet, and on 

 reaching the more open ledges of the former, at about 2,200 feet, 

 at once noticed the numbers of Blackpolls that were passing. 

 Many single birds flew by overhead at short intervals and at no 

 great distance above the mountain; most of them were going 

 northward in the face of a light wind, but a number stopped 

 among the clumps of small spruces, balsams and birch which 

 grew among the'ledges. A few also were seen in company with 

 small flocks of chickadees and on all sides was heard their fine 



