xii INTRODUCTION. 
fairies; but baffled by storms and contrary gales, they often 
suffer from want, and at times, like the Quails, become victims 
to the devouring waves. On such unfortunate occasions (as 
Mr. Bullock! witnessed in a voyage near to Vera Cruz late in 
autumn), the famished travellers familiarly crowd the decks of 
the vessel, in the hope of obtaining rest and a scanty meal 
preparatory to the conclusion of their unpropitious flight. 
Superficial observers, substituting their own ideas for facts, 
are ready to conclude, and frequently assert, that the old and 
young, before leaving, assemble together for mutual departure ; 
this may be true in many instances, but in as many more a 
different arrangement obtains. The young, often instinctively 
vagrant, herd together in separate flocks previous to their 
departure, and guided alone by the innate monition of Nature, 
seek neither the aid nor the company of the old ; consequently 
in some countries flocks of young of particular species are alone 
observed, and in others, far distant, we recognize the old. 
From parental aid the juvenile company have obtained all that 
Nature intended to bestow, — existence and education; and 
they are now thrown upon the world among their numerous 
companions, with no other necessary guide than self-preserving 
instinct. In Europe it appears that these bands of the young 
always affect even a warmer climate than the old; the aération 
of their blood not being yet complete, they are more sensible 
to the rigors of cold. The season of the year has also its effect 
on the movements of birds; thus certain species proceed to 
their northern destination more to the eastward in the spring, 
and return from it to the south-westward in autumn. 
The habitudes and extent of the migrations of birds admit 
of considerable variety. Some only fly before the inundating 
storms of winter, and return with the first dawn of spring; 
these do not leave the continent, and only migrate in quest of 
food when it actually begins to fail. Among these may be 
named our common Song Sparrow, Chipping Sparrow, Blue- 
bird, Robin, Pewee, Cedar Bird, Blackbird, Meadow Lark, and 
many more. Others pass into warmer climates in the autumn, 
1 Travels in Mexico, 
