64 Galapagos Islands 



Dipnoi are very archaic, and all are extinct save 

 three; it is striking to find that one of these (Cera- 

 todus) occurs in Queensland, another (Lepidosiren) 

 in the Amazons, and a third (Protopterus) in certain 

 African rivers. Similarly the primitive pioneer Verte- 

 brates known as lancelets (Amphioxus) have a wide 

 distribution near the coasts of warm and temperate 

 seas. The ancient king crab (Limulus) lives in shal- 

 low water off sandy shores from Maine to Florida ; it 

 occurs in the West Indies, and also off the Molucca 

 Islands in the Far East. We shall refer later to the 

 wide distribution of the old-fashioned or primitive 

 types known as Onychophora and Enteropneusta. 



THE GALAPAGOS ISLANDS 



Instead of making more general statements let us 

 take a particular case that is very instructive in more 

 ways than one — the case of the Galapagos Islands, 

 studied by Darwin on his Beagle voyage, and recently 

 by Mr. William Beebe, traveller-naturalist to the 

 New York Zoological Society. 



Long before the beginning of the age of man, a 

 great peninsula stretched from Central America 

 southwards into the Pacific. It was an Ultima Thule 

 except that it lay in the wrong direction, not north- 

 wards but verging on the equator. It was a land of 

 volcanoes and far from hospitable. Ages passed, and 

 the great land-bridge was broken ; the peninsula be- 

 came an island, five hundred miles or so west of 

 Ecuador. The subsidence continued and the island 

 became an archipelago, with the tops of the cold 



