xliv Proceedings. 



be distinguished from each other by the shape of their wings. 

 The wings of nou- migratory birds were rounded, and the end or 

 flight-feathers were almost all of the same length, and were 

 small ; whereas in migratory birds, like the swift, they were 

 enormously developed, as if the whole vital energy had gone into 

 the flight-feathers. It should be particularly noticed that birds 

 never bred in the south and then migrated to the north. They 

 always bred in the farthest north. Thus every bird that came to 

 breed in this country went farther south for its winter quarters, 

 and every bird that came here for its winter quarters bred farther 

 north. Birds did not migrate simply from a whim, but because 

 there was a reason for it, and the cause of the migration must be 

 taken to be almost entirely want of food. It was very improbable 

 indeed that birds migrated simply to avoid cold. They were 

 able, in the course of ages at least, to provide themselves with 

 inv coats, so closely packed to their bodies that they really 

 rendered themselves impenetrable to cold. One of the causes 

 for birds migrating originally was, probably, because every bird 

 has to be constantly increasing its range or trying to do so. 

 There was throughout the animal creation, as through the vege- 

 table creation, an enormous struggle for existence constantly 

 going on. It was difficult to I'ealise the vastness and extent of 

 that struggle. But he thought he would be able to make them 

 realise to some extent to what an enormous degree it must 

 operate upon the animal world by an example. Supposing they 

 were to take a pair of partridges and put them in the fields out- 

 side Croydon, and supposing those partridges were to build a 

 nest and lay eighteen eggs, as they frequently did, and hatched 

 them all, and allowing that process to go on for sixteen years, 

 each pair of young birds laying eighteen eggs and hatching them, 

 then at the end of sixteen years there would not be room on the 

 whole surface of the earth for those birds to stand, without 

 standing on each other's backs. So they could see there must 

 be annually an immense mortality among birds, and there was 

 no doubt that a great deal of that mortality took place during 

 the migration." 



He then described the great lines of migration in Europe and 

 Asia, pointing out that in some cases these routes follow the 

 lines of ancient coast-lines long since submerged, showing the 

 enormous antiquity and unchanging character of the instinct. 

 He gave a most graphic and interesting account of his own 

 observations in Hehgolaud. This island lies on the direct track 

 of one of the greatest lines of migration between Arctic Europe 

 and England, and South Germany ; and the vast multitudes of 

 birds which pass over it seem almost incredible. 



Mr. Seebohm related how (quoting again from the ' Clu-onicle') 

 "he had been round the island one day twice with his guu, 



