512 NOTES ON SOME OF THE 
ever, seem actually fixed at all seasons, and are really essen- 
tially non-migratory, as the Spruce Partridge, and Quail 
(Ortyx Virginianus) are in New England. But only a small 
proportion, doubtless, of the so-called non-migratory birds 
at any given locality are really so.* 
In connection with this topic of migration, the fact that 
some of the young or immature individuals of our marine 
birds, as the Herring Gull (Larus argentatus) and other 
species of that family, and several of the Trings, linger on 
our coast during summer, while the adult all retire north- 
ward, is:one of some interest. Mature and strong birds 
only, in species that breed far to the north, evidently seek 
very high latitudes. Birds of the first year also appear to 
roam less widely than the older. In different species of the - 
Gull family it is generally only the mature birds that in 
winter are seen far out at sea, though in the same latitudes 
the young may be numerous along the coast. All observant 
collectors are well aware of the fact that those birds that 
first reach us in the spring, of whatever species, are gen- 
erally not only very appreciably larger, but brighter plum- 
aged and in every way evidently more perfect birds than 
those that arrive later; and that in those species that go en- 
tirely to the north of us there is a much larger proportion of 
paler colored and immature birds, especially among the Sylvi- 
colide, or warblers, towards the close of the migrating season 
than earlier. Hence the presence here of a few individuals 
in summer of species that usually go farther north is not 
always sufficient evidence that the species breeds with us. 
In reference to the notes which follow, they may be consid- 
ered as forming a supplement, as already stated in a foot note; 
to a "Catalogue of the Birds of Massachusetts" published 
by me five years since. In the present paper seven species f 


Pour S MUS + 
; pect t proof wł this proposit ts, y remarks on this point 
dn the Memoirs of the Boston Society of Natural History, Vol. i, Pt. iv, p. 488 (foot 
Bote). 




a Se tStr ix pratincola, Surnia ulula, Turdus nevius, Seiurus Ludovicianus, Centrony* 

