508 NOTES ON SOME OF THE 



reliable authorities, because in particular instances they do 

 not accord with their own observations. Neither should 

 differences in habits, in song, etc., be taken as infallible 

 evidence of a difference of species. It is well known that 

 in Massachusetts the Brown Thrush (HarporliyncJms rufus) 

 is not uniform in the location of its nest, as about Spring- 

 field it almost invariably builds on the ground (in the many 

 scores of nests that I have seen there I have met with but a 

 single exception), while in other localities it as invariably 

 places its nest a little above the ground in bushes. At 

 Evanston, 111., I once found one in an oak higher than I 

 could reach ; the locality, however, was swampy. How 

 universally the Chipping Sparrow (8pizella socialis) breeds 

 in trees, and generally at an elevation of several feet, is well 

 known, but several authentic instances of this bird's nesting 

 on the ground have come to my knowledge, one of which I 

 myself discovered. Variations of this character in other 

 species are of occasional occurrence, examples of which have 

 doubtless been met with by every experienced collector. 



The materials which birds select in the construction of 

 their nests are well known to vary in different localities ; 

 the greater care exhibited by some species to secure a soft 

 warm lining at the north that are much less precautions 

 in this respect at the south, is already a recorded fact. 

 Aside from this, the abundance of certain available materials 

 occurring at only particular localities gives a marked char- 

 acter to the nests there built, which serves to distinguish 

 them from those from other points. Some of the Thrushes, 

 for instance, make use of a peculiar kind of moss at some 

 localities that elsewhere, from its absence, are compelled to 

 substitute for it fine grass or dry leaves. At Ipswich, on 

 Cape Cod, and perhaps generally in the immediate vicinity 

 of the sea, the Purple Grackles (Quiscalus versicolor) and 

 Red-winged Blackbirds (Agelceus phceniceus), and in fact 

 numerous other species, in building their nests often use 

 little else than dry eel-grass or "sea-wrack," which results in 



