of the Galapagos Archipelago. 259 
of intercourse, especially atmospheric storms, between the several islets, and 
argues no physical peculiarity or want of vigour in the species themselves. 
Supposing all the species now inhabiting the Galapagos to be doiectóa on à 
continuous surface, equalling in area the aggregate of the islets forming fint 
archipelago, then would the Flora lose much of its characters; the strife with 
its neighbours for position, which marks all stages of the life of any two or 
more contiguous plants, would terminate in a few replacing the many, and the 
introduced species bearing a greater proportion to the indigenous, whilst the 
individuality of the Flora would thus be lessened in degree or wholly de- 
stroyed. It must be admitted, that the first steps towards ensuring the conti- 
nuance of many species in a given area, are to isolate them, and to cut off the 
means of migration; exactly as in a garden the plants are protected from en- 
croachment mechanically, and the seeds of the more volatile collected betimes, 
to prevent a like effect being naturally brought about. 
Though, however, this in some degree explains why the florule of the 
islets should be distinct in character, it can give no clue to the representation 
of species amongst them ; which representation, whether it be regarded in the 
light of the whole group bearing the imprint of America, with but few of the 
productions of that continent, or of the several islets each individually distinct 
combining to form an harmonious whole, is a mystery which it is my object 
to portray, but not to explain ; and I shall proceed to show the amount of this 
difference, and its relation to the physical features of the islets. 
The following table shows the amount of peculiarity in each island of flowering 
plants and ferns, and the proportion confined to itself; those common to itself 
and one or more other islets; and such as are found on the American continent. 
: Total number of | „Confined to Galapagos, |j. iiio peculi Confined to the 
Name of island. : i. e. total excluding those yp vs but fi ike! 
T: common to rent n to the islet, aia Me he 
Charles Island .... 96* 47 39 13 
James Island ..... 100 48 38 10 
Albemarle Island .. 47 27 20 7 
Chatham Island `.. 40 21 17 4 
Whole group .... 253 123 16 
* I have excluded seventeen species from the flora of this islet, 
with cultivation. 
VOL. XX. 2M 
as being almost certainly introduced 
