Birds of Massachusetts. 239 
the weakest behind ; and thus they set forth, some- 
times with an extended front, sometimes in single 
file, but generally in a sharp angle, with an old 
gander at the head. When any one is fatigued, he 
falls baek in the wake of another, who cleaves the 
air before him ; the leader at times gives out a loud 
ery of encouragement, or command, which is an- 
swered from various parts of the line. 'They fly 
with great strength and steadiness, at a great height 
in the air, if they have far to go; but when doubt- 
ful of the season, they fly lower, and are often be- 
wildered in fogs and snow storms, so as to come to 
the ground stupified, and to submit quietly to their 
fate. ‘They are so much alive to changes of temper- 
ature, that, when they are seen returning over their 
line of march, it indicates that a change of weather 
is nigh. 
When they alight in some place where they intend 
to pass the night, they crop the grass sidewise, 
like the domestic goose, or pat the ground with both 
feet to force the worms out of it. Sometimes they 
alight in corn-fields, where they do considerable 
damage; sometimes in the water, where they 
plunge their heads to the bottom in seareh of food. 
They always keep sentinels stationed, who, at the 
approach of cattle, are silent; but if a bear, or pan- 
ther, or worse than all, a man comes nigh, the alarm 
is given, and all glide into the nearest water and 
swim to a distance from the shore. Their sense of 
hearing is wonderfully quick and discerning ; they 
can at once distinguish a sound made by man. 
The crossing of the breed of the wild with the 
E 
