llera to the highlands of Brazil. It may be observed that some
(though not strong) reasons can be assigned for believing that at about
this same period the two Americas were not so thoroughly divided as they
now are by the West Indies and tableland of Mexico. I will only further
remark that the present most singularly close similarity in the
vegetation of the lowlands of Kerguelen's Land{373} and of Tierra del
Fuego (Hooker), though so far apart, may perhaps be explained by the
dissemination of seeds during this same cold period, by means of
icebergs, as before alluded to{374}.

{370} Opposite to this passage, in the margin, the author has
written:--"too hypothetical."

{371} The Cordillera is described as supplying a great line of
invasion in the _Origin_, Ed. i. p. 378.

{372} This is an approximation to the author's views on
trans-tropical migration (_Origin_, Ed. i. pp. 376-8). See
Thiselton-Dyer's interesting discussion in _Darwin and Modern
Science_, p. 304.

{373} See Hooker's _Lecture on Insular Floras_ in the _Gardeners'
Chronicle_, Jan. 1867.

{374} <Note by the author.> Similarity of flora of coral islands
easily explained.

Finally, I think we may safely grant from the foregoing facts and
reasoning that the anomalous similarity in the vegetation of certain
very distant mountain-summits is not in truth opposed to the conclusion
of the intimate relation subsisting between proximity in space (in
accordance with the means of transport in each class) and the degree of
affinity of the inhabitants of any two countries. In the case of several
quite isolated mountains, we have seen that the general law holds good.

_Whether the same species has been created more than once._

As the fact of the same species of plants having been found on
mountain-summits immensely remote has been one chief cause of the belief
of some species having been contemporaneously produced or created at two
different points{375}, I will here briefly discuss this subject. On the
ordinary theory of creation, we can see no reason why on two similar
mountain-summits two similar species may not have been created; but the
opposite view, independently of its simplicity, has been generally
received from the analogy of the general distribution of all organisms,
in which (as shown in this chapter) we almost always find that great and
continuous barriers separate distinct series; and w