12 BIKDS OF ONTARIO. 



up from the south in spring. All this information is the result of 

 much time and care having been devoted to the subject by a host of 

 observers, and it is very valuable to those interested in the subject, 

 but the general questions relating to bird migration still remain 

 unanswered, and the student may as well begin at the beginning and 

 try to discover : " Why do birds migrate 1 How do they know 

 where to go 1 " 



With regard to those hatched in the north, we can readily under- 

 stand that the failure of food supply at the time when insect life 

 is wiped out, and the fields and marshes are buried under deep snow, 

 makes a change of climate an absolute necessity. Then comes the 

 second question : " How do they know where to go ? " The answer 

 to this is, that they are guided by the observations of the older 

 members of the flock, and to a great extent by the exercise of 

 inherited memory, that is, the memory inherited of what has been 

 done by other birds of the same species for countless generations. 



Of inherited memory we cannot speak from experience, for it is 

 not inherent in our nature, but that birds do possess the faculty is 

 evident from many of their common habits. Take, for instance, that 

 of nest-building. Different species of birds build very different kinds 

 of nests, and often in very different situations, but birds of any 

 given species usually build the same kind of nest, year after year, in 

 the same kind of situation. That this regularity is not the result of 

 personal observation is also quite apparent. For example, a pair of 

 Grassfinches build their nest on the ground under a bunch of weeds 

 or a little bush. The eggs are therein deposited, and in due time 

 the birds are hatched. They grow quickly, and soon begin to feel 

 crowded in the limited space. Presently, along comes a sportsman's 

 dog with glaring eyes, and his tongue lolling out of his open mouth. 

 He stares and snuffs at the tiny objects, and they hurry off in terror 

 to hide among the brambles, where their wants are attended to 

 by their parents for a few days until they are able to shift for 

 themselves, which they soon do without having once seen the nest 

 in which they were hatched. Yet in spring, when the different 

 members of this little family start housekeeping on their own 

 account, each one builds a nest precisely like that from which they 

 were scared by the dog. 



We can see at once the great value of this gift to the birds 

 while pursuing their long and hazardous journey, much of which is 

 performed during the hours of darkness, the daylight .being necessary 

 to enable them to secure the food which they require by the way. 



