CHAPTEE XII 



THE GALAPAGOS ISLANDS 



Right on the Equator, off the west coast of South America, 

 in the Pacific Ocean, lies a small group or archipelago of 

 islands known as the "Galapagos islands." There are five 

 large islands and twelve small ones, the most extensive 

 (Albemarle) being about eighty miles long and of very irre- 

 gular shape, while the four next in importance (Chatham, 

 Indefatigable, James and Narborough) are each about twenty 

 or thirty miles in length, and of a rounded or elongate form. 

 They are best seen on the map representing the range of 

 Helicina (Pig. 11) being situated within the circle nearest 

 South America. The climate of the islands is cooler than 

 that of any other equatorial land at sea-level, because the 

 temperature of the surrounding water is singularly low. This 

 is caused by the Humboldt current, which strikes the islands 

 during its north-westerly course on its way from the cold 

 southern regions. The lower slopes of the islands suffer from 

 want of rain. At a height of a thousand feet and upwards 

 sufficient moisture is condensed to provide for a fairly 

 luxuriant vegetation. 



The Galapagos islands differ in two important respects from 

 many of the West Indian islands. They are entirely formed 

 of volcanic rocks, according to Mr. Darwin, who gave us the 

 first reliable description of them, and they are situated at the 

 great distance of seven hundred and fifty miles from the main- 

 land of South America. The nearest land, apart from the 

 small Cocos islands, is Ecuador, to which state the Galapagos 

 archipelago now belongs. In the case of the Antilles almost 

 all authorities are agreed that the nucleus of the fauna re- 

 presents survivals from the time when the islands were joined 

 to the mainland, and that accidental distribution has not 

 greatly modified the original fauna. In the Antilles we meet 



