MIGRATION IN ITS BEARING ON LAMARCKISM 105 



boreans, the garden of the Hesperides, the Fortunate Islands, and 

 the Elysian Fields are but faint and imperfect reminiscences of 

 the lovely and favored climes of Sweden, from which the Greeks 

 themselves derived their alphabet, their astronomy, and their religion. 



To the men of the north home seems the natural refuge of the 

 birds, and, as much of the literature of migration is northern, 

 the birthplace of summer birds has been regarded as their true 

 or natural home, and while their disappearance in winter has 

 seemed to call for explanation, their return in summer has been 

 regarded as a matter of course, for the intense love of home 

 which many exhibit has seemed enough to draw them back when 

 the season of scarcity is over. 



It is the " homing " instinct which makes the carrier pigeon so 

 useful to man; and one of the most impressive features of the 

 migratory habit is the definiteness of the journey northwards, 

 which often leads to a particular bush or ledge of rocks. Many 

 species of our common birds lay their eggs year after year in the 

 same nest, although they may spend the rest of the year in the 

 heart of a strange country thousands of miles away, and although 

 the chosen spot may have changed so much that it is no longer 

 a judicious selection. 



A bottle in the branches of a tree at Oxbridge in England is 

 known to have been occupied every year, with only one exception, 

 since 1785, by a pair of blue titmice; and on a hill in Finland, 

 well known to tourists as the most southern point in Europe 

 where the sun may be seen at midnight, a nest is said to have 

 been occupied by a pair of peregrine falcons ever since the visit 

 of the French astronomer Maupertius in 1736. There are other 

 records of similar instances, and while it is not probable that the 

 birds which visit a nest year after year for centuries are the same, 

 the fact is all the more remarkable if they belong to successive 

 generations. 



According to folklore some of the summer birds do not go 

 away, but hide near home, and Carus, in his history of zoology, 

 refers to several learned writers who, early in the seventeenth 

 century, quoted from the older literature much venerable authority 

 for the belief that the swallows hide through the winter in holes 

 and clefts in the rocks, or even under the water. 



