3i6 



CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



education extends to a comprehension of the plan of migra- 

 tion. However, it seems plain, with the example and 

 guidance of the old, migration could become in time a ruling 



Habit in the life of a last summer's bird, holding it true to 

 route and period of movement. In short, it is believed that 

 the causes of migration are simple facts and not impene- 

 trable mysteries lying beyond the domain of scientific 

 enquiry. 



Summary. — To sum up the whole matter in a single sen- 

 tence : It is held that bird migration is a habit evolved by 

 education and inheritance which owe their origin and per- 

 petuation to winter with its failure of food. 



Migration 



