26 Zbe Warbler 



ciliated to produce a certain effect by the agency of certain means without 

 any of that chain of thought which is an essential quality of reason. This 

 is called instinct, a term which has given rise to various theories, which as 

 it would require volumes to explain, and would even then be unsatisfactory) 

 I shall pass over with a few remarks in explanation of the term. 



When certain species of birds at their first season build all of their 

 nests in a similar form, and of similar materials without having seen any 

 others or had any experience themselves — this may be called instinct. On 

 the other hand, when man guards against danger or makes provision for the 

 wants of life — or seeks relief from diseases by the application of medicines, 

 he acts from reason. He is instructed by the experience of the past. When 

 birds at certain seasons of the year change the climate in anticipation of the 

 cold or heat, they act from instinct; because to many of them it is their first 

 migration, and as many of them migrate not in flocks, but singly, no exper- 

 ience can aid them. On the other hand, when man makes provision for 

 the changes of seasons and climate he acts from reason — he is instructed by 

 his own experience or the experience of others. 



Whatever difficulties there may be in accounting for that mysterious 

 principle in birds called instinct and which induces them at certain seasons 

 to change their abode, and again after an interval of six months to return to 

 the neighborhood where they reared their young a year before. The facts 

 of these migrations aie incontrovertible, and the reasons why they take 

 place are becoming more and more apparent. Those birds that migrate are 

 from the very structure of their bodies admirably adapted to rapid and con- 

 tinued flight. Their feathers are so light that they float in the atmosphere 

 for many hours without any artificial support. The tubes of these feathers 

 are hollow, the bones are specifically lighter than those of quadrupeds; are 

 also hollow, and instead of marrow are filled with air. They are furnished 

 with lungs of unusually large size, adhering to the ribs provided with aerial 

 sacs insinuating themselves into the abdomen. These added to the great 

 length and strength of wing enables them with ease and rapidity to navigate 

 the air, to elevate themselves above the clouds and pass from one country 

 and climate to another 



We perceive then, from the very structure of birds that they are admir- 

 ably formed for rapid flight and migration. From a variety of accurate ex- 

 periments which have been made at different periods it appears that the 

 Hawk, the wild Pigeon {Columba mygratoria) and several species of wild 

 Ducks fly at the rate of a mile in a minute and a half. This is at the rate of 

 48 miles an hour, 576 between the rising and setting of the sun and n 52 

 miles in 24 hours. This would enable birds to pass from Charleston to our 

 distant northern settlements in Canada in a single day, and this easily ac- 

 counts for the circumstance that Geese, Ducks and Pigeons have been taken 



