508 NOTES ON SOME OF THE 
reliable authorities, because in particular instances they do 
not aecord 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 (Harporhynchus 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 
plaees its nest a little above the ground in bushes. At 
Evanston, Ill., I once found one in an oak higher yc I 
could reach; the locality, however, was swampy. 
universally the Chipping Sparrow (Spizella socialis) an 
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 à soft 
warm lining at the north that are much less precautious 
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- 
notin’ ia 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 Mec 
of the sea, the Purple Grackles (Quiscalus versicolor) and 
Red-winged Blackbirds (Ageleus pheniceus), and in fact 
. humerous other species, in building their nests often use 
— - x else than dry eel-grass or “sea-wrack,” which results in 





