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FLORA OF THE GALAPAGOS ISLANDS. 239 
(1), 622, to Chatham Island, is with scarcely a doubt an erroneous 
determination. 
While it is thus clear that the Galapageian flora is only an outlying 
portion of the American flora with a strong specific differentiation, it is 
impossible to trace its relationship closely to any one section of the 
Pacific American vegetation. It can only be said in a general way that 
nearly all the plants of the archipelago are identical with, or obviously 
related to, species of the Sierras and Andes or of the Pacific Slope 
between Lower California on the one hand and northern Chili on the 
other. The xerophytic elements in the Galapageian flora show a con- 
siderable resemblance to the desert flora of southern Peru and the drier 
parts of the Andes. ‘The mesophytes, on the other hand, correspond 
most nearly to plants of Ecuador, Colombia, Central America, and 
southern Mexico. ; 
Those who have written upon the phytogeography of the Galapagos 
Islands have frequently mentioned the West Indian affinities of the flora, 
but here I can find no close resemblance or significant relationship. 
It is to be noticed that Hooker, who first employed the term “ West 
Indian ” regarding the flora of the Galapagos Islands, either used it to 
include, or expressly qualified it by the addition of, the flora of Panama 
and the adjacent lowlands of the continent, —a qualification which has 
not always been sufliciently regarded by subsequent authors. But, on 
the other hand, the discoveries of*the last half century have shown a 
much greater difference between the flora of the Antilles and of the 
Panama region than was to be inferred when Hooker wrote ; so although 
a definite relationship can be traced between the Galapageian flora and 
that of the lower slopes of Colombia, it does not follow that there 1s 
any marked affinity to the flora of the West Indian Islands. Indeed, 
of the species common to the Galapagos and the Antilles there are 
none (if we except a sterile and doubtfully identified specimen of the 
Cuban Cenchrus distichophyllus) which do not also occur upon the adja- 
cent parts of the continent, and nearly all, like the halophytes of the 
Shores, are species of wide tropical distribution. 
Hooker (4), 239, 250, drew attention to what ap 
esting double relationship between the plants of t og 
and those of other regions, as follows: “ Here, as in other COmNEEN, t o 
vegetation is formed of two classes of plants, — the one peculiar ae 
group, the other identical with what are found elsewhere. In this there 
are even indications of the presence of two nearly equal F gree eas an 
digenous and introduced, — and these are of a somewhat different stamp 5 
peared to be an inter- 
he Galapagos Islands 
