OF ARTS AND SCIENCES II 



migrant birds is sometimes found upon successive days, the 

 membership of which shows that many of the insectivorous birds 

 are lingering there, finding an ample supply of food on the trees 

 infested with the aphis. This grove has proved in recent sea- 

 sons one of the treasure islands for the rarer migrant warblers 

 as well as for Philadelphia Vireos and other uncommon species. 

 A somewhat similar growth along the railroad at Jefferson Junc- 

 tion in the vicinity of Cherry and Little Cherry Ponds has 

 afforded another location in which a good collection is likel}- to 

 be found. At either place fifteen species of warblers have some- 

 times been identified in association with other birds during an 

 hour's stay. 



In this Jefferson region I have carried on active and sj-stem- 

 atic observation for twelve successive seasons, beginning with 

 1899. The period of ni}- observation year by year has extended 

 from late May or the first da3-s of June to the early days or the 

 middle of October. Each succeeding season the occupation has 

 been prosecuted with closer attention and a fuller allotment of 

 time. Thus the data obtained are the result of an increasingly 

 careful search. That they are not yet complete, although, per- 

 haps, approximately so, is a stimulating thought for 3^ears yet 

 before me, it may be. During the last eight seasons I have had 

 the valuable aid of my assistant, Mr. Edward D. Parker, who 

 has been my intelligent companion on all trips by horse and upon 

 all mountain climbs and longer walks. By his alertness and 

 accurac}^ of sight and hearing he has rendered most valuable 

 service. Others have shared also in walks and drives for 

 observation and have contributed to the sum of knowledge 

 gained. These will not be named except in specific cases where 

 a rarer bird was seen. Species which appear only during the 

 late fall, the winter, and the early spring have not come under 

 the writer's observation. But these, most happily, have been 

 added to the list by Mr. F. B. Spaulding of Lancaster, who also 

 contributes a number of interesting casual records. Mr. Spauld- 

 ing furnishes exclusively twenty-four species and has also con- 

 tributed many valuable data which have been incorporated in 



