AN ORNITHOLOGICAL LECTURE. 99 



men recognize the fact that the snipe and woodcock have 

 returned, not because the rigorous winter days are wholly 

 passed, but because the frost is sufficiently out of the ground 

 to allow the worms to come to the surface ; and know that 

 in warm, springy meadows these birds may often be found 

 all through the year. Man no doubt influences the mi- 

 gratory habits of birds. To many he offers inducements 

 in the shelter, and in the abundance of insects which his 

 industry occasions, to linger later in the fall than was their 

 wont, and return earlier in the spring. While, on the con- 

 trary, the persecution which the shy wild- fowl have received 

 has caused them generally to repair to secluded breeding- 

 places, far north of their haunts of fifty years ago. But 

 the migrations of most birds are somewhat irregular, and 

 we have so few reliable data that we can hardly yet deter- 

 mine the laws which govern their seasonal movements, 

 much less assert the ancient origin of the " migratory in- 

 stinct," so called, or state the varied influences that have 

 led to the present powerful habit, and have pointed out 

 the routes which the flocks now follow, spring and fall. 

 The geologist must aid the zoological student in solving 

 these problems. 



The true home of a bird, then, is where it rears its young, 

 even though it be not there more than a third of the year, 



