236 Dr. J. D. Hooxer on the Vegetation 
is the case with the Fauna, many of the species, and these the most remark- 
able, are confined to one islet of the group, and often represented in others 
by similar, but specifically very distinct congeners. 
This examination has led me to take a survey of the vegetation of several 
other tropical islands, whose plants present much peculiarity, and to trace 
the effects of isolation in geographical position upon vegetation ; as well as 
certain characters in some orders, their distribution and proportions, which 
seem to distinguish insular floras from the continental. 
Before entering upon the details of the vegetation, I shall shortly allude to 
the position of the Galapagos, and some of their most important features of 
climate and soil which affect the plants, and which I shall extract from the 
Journals of Mr. Darwin and of other voyagers, including one by the late 
Mr. T. Edmonstone, hitherto unpublished. 
The Archipelago consists of ten islands situated under the equator, between 
500 and 600 miles west of the mainland of America at Guayaquil, and the same 
from the Isthmus of Panama, which lies to the north, and 3000 miles from the 
nearest of the tropical Pacific islands. The islets are wholly volcanic; several 
of the peaks attain a height of 3000 to 4700 feet, some having their flanks 
studded with innumerable small craters. These are considered to have been 
formed in the sea, and to be, as compared to the adjoining continent, of recent ` 
formation. 
The climate is far from intensely hot, being moderated both by the insularity 
of their position and the low tem perature of the waters of the great south-polar 
current which washes their shores. The extremes of temperatures observed at 
different times of day between 9 a.m. and 3 P.M. for thirty-five days in Septem- 
Stood at 85° only in the wind and sun, but which, when plunged into the soil, 
rose at once to 137°, and would have risen higher had the tube been longer. 
On the other hand, nocturnal radiation does not in all probability reduce the 
temperature proportionally, the nights being generally misty. The prevailing 
weather is overcast and gloomy, the winds varying for the period alluded to 
