42 PHILOSOPHY OF ZOOLOGY. 



Those birds which feed during the night may be expect- 

 ed to perform their migrations during the same interval, it 

 being the season of their activity ; while those birds which 

 feed during the day, may be expected to migrate with the 

 help of light. Tlie migrations of the woodcock and quail 

 confirm this conjecture. The woodcocks arrive in this 

 country during the night, and hence they are sometimes 

 found in the morning after their arrival, in a neighbouring 

 ditch, in too weak a state to enable them to proceed. 

 Poachers are aware that they migrate during the night, 

 and sometimes kindle fires on the coast, to which the wood- 

 cocks, attracted by the light, bend their course, and in this 

 manner great numbers are annually destroyed. Quails, on 

 the other hand, perform their migrations during the day, 

 so that the sportsman in the islands of the Mediterranean 

 can use his dog and gun. 



It has often excited surprise in the minds of some, how 

 migrating birds could support themselves so long on wing, 

 as to accomplish their journeys, and at the same time live 

 without food during their voyage. These circumstances 

 have induced many to deny the existence of migration, and 

 have excited others to form the most extravagant theories on 

 the subject, to account for the preservation of these birds 

 during the winter months. But the difficulties which have 

 been stated, are only in appearance, and vanish altogether 

 if we attend to the rapidity of the flight of birds. 



The rapidity with which a hawk and many other birds 

 occasionally fly, is probably not less than at the rate of 150 

 miles in an hour. Major CARTWRIGHT, on the coast of La- 

 brador, found, by repeated observations, that the flight of 

 an eider duck (Anas molissima) was at the rate of 90 

 miles an hour. Sir GEORGE CAYLEY computes the rate 

 of flight, even of the common crow, at nearly 25 miles an 



