CHAPTEE XII 
THE GALAPAGOS ISLANDS 
Eight 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 (Fig. 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, arid that accidental distribution has not 
greatly modified the original fauna. In the Antilles we meet 
