INTELLIGENCE IN BIRDS. 121. 
one generation to another. Many young birds left to 
themselves, without example of the older ones, would 
not go south at the approach of cold weather unless by 
accident. Those hatched too late to move with others 
of their kind often wander about aimlessly until they 
perish with the cold. Birds that are brought across the 
ocean from countries where climate does not render a 
change necessary do not fly south at the approach of 
winter. The English sparrows survive by their extreme 
hardiness, otherwise they would perish like other imini- 
grants. The partial failure in the introduction of the 
skylarks into this country is due solely to the lack of 
knowledge on the part of the birds concerning the cli- 
matic changes. They have not learned the necessity of 
moving to lower latitudes, and nof having the example 
of their elders, nor the instinct transmitted from ances- 
tors, they remain north in the fall and perish with the 
cold. 
In nothing do the birds display greater sagacity or 
show more clearly their exercise of reasoning powers 
than in some of the phases of their migration. It is yet 
one of the mysteries of nature how they find their way 
back over a distance of thousands of miles, to the very 
tree or stump or barn in which they nested the year 
before. Do they remember familiar objects noted on 
their southern journey, or do they remember only direc- 
tion, and, like the honey bee, “strike a bee line” towards 
their destination? The theory of “ widening circles of 
flight” cannot be true, as this would take them into 
such extremes of heat and cold as to make it impossible: 
