MUSEUM OF COMPARATIVE ZOOLOGY. 57 
Charles Island in 1831. After the disappearance of the convicts, they 
were occasionally visited by the orchilla traders, who cut down the 
scanty forests for the sake of obtaining more easily the valuable moss 
growing on the trees. 
Dr. Theodor Wolf,! Ecuadorian State Geologist, has given a most 
interesting account of his visit to the islands, supplementing in many 
ways the account we owe to Darwin in his “ Voyages of the Adventure 
and Beagle,” and his ‘ Volcanic Islands.” 
Tur FLORA or THE GALAPAGOS. 
Dr. Wolf has given a most characteristic description of the three belts 
of vegetation, which can be recognized on all the islands. (Plates XV.— 
XX.) The lower or more barren belt, characterized by its stunted vege- 
tation, consisting near the beaches of salt-loving plants, probably all im- 
migrants from the mainland, followed by grayish white apparently dry 
bushes, with small leaves and inconspicuous blossoms, the most common 
of which are a Verbena bush and a species of Acacia, with a large tree, 
the Palo Santo, which grows to a height of thirty feet. Where the lava 
fields seem to prevent the growth of any other plants, we find a tree-like 
Opuntia and a huge Cereus (Plate XX.). The last disappear as we rise, 
and on reaching the so called high plateau, the Acacia and Palo Santo 
increase in size, and the Verbena vanishes. When we reach the second 
belt, the lava blocks have become decomposed into a soft reddish earth 
by the action of the moisture from the prevailing trade winds, which blow 
refreshingly across from the south, and, carrying with them masses of 
moisture, have completely changed the aspect of the vegetation on the 
plateau (Plate XVII), and of the weather side of the islands. The woods 
are green, composed of small trees, principally recalling the Polylepis of 
the Andes; they are open, their paths separated by grassy plots, till we 
eradually pass into the last and highest region, bare of trees, and cov- 
ered by a rather coarse grass, which extends to the highest summits of 
the islands (Chatham, Charles, Indefatigable, and James). 
Chatham Island is noteworthy for the special development of the lower 
voleanic barren region, and of the higher and grassy woody district, and, 
in addition, is distinguished by the barren voleanic tract which forms 
the eastern extremity of the island, on which, as we sailed by, we could 
scarcely distinguish any trace of vegetation, — the whole a mass of 
blocks of volcanic rock scattered between the numerous small volcanoes 
1 Ein Besuch der Galapagos Inseln, mit drei Kärtchen. Heidelberg, 1870. 
