Origin of Species Variorum

Comparison with 1866

the same; but much oftener they are specifically distinct, though plainly related to each other in a remarkable manner. ↑

This brief abstract applies to plants alone: some strictly analogous facts could be given on the distribution of terrestrial animals. In marine productions, similar cases occur; as an example, I may quote a remark by the highest authority, Prof. Dana, that "it is certainly a wonderful fact that New Zealand should have a closer resemblance in its crustacea to Great Britain, its antipode, than to any other part of the world." Sir J. Richardson, also, speaks of the reappearance on the shores of New Zealand, Tasmania, &c., of northern forms of fish. Dr. Hooker informs me that twenty-five species of Algæ are common to New Zealand and to Europe, but have not been found in the intermediate tropical seas. ↑

It should be observed that the northern .. forms found on the mountain-ranges of the ... intertropical regions and in the southern parts of the southern hemisphere are not arctic, but belong to the temperate zones: as Mr. H. C. Watson has recently remarked, "in receding from polar towards equatorial latitudes, the Alpine or mountain floras really become less and less arctic." Of these forms, some few are identical with northern temperate species, or are varieties of them, whilst others are ranked by all naturalists as closely allied to, but specifically distinct from, their northern representatives.

Now let us see what light can be thrown on the foregoing facts, on the belief, supported as it is by a large body of geological evidence, that the whole world, or a large part of it, was simultaneously colder during the Glacial period than at present.

the same; but they are much oftener specifically distinct, though related to each other in a most remarkable manner. ↑

It should be observed that the northern species and forms found in the southern parts of the southern hemisphere, and on the mountain-ranges of the intertropical regions, are not arctic, but belong to the northern temperate zones. As Mr. H. C. Watson has recently remarked, "In receding from polar towards equatorial latitudes, the Alpine or mountain floras really become less and less arctic." Many of the forms living on the mountains of the warmer regions of the earth and in the southern hemisphere are of doubtful value, being ranked by some naturalists as specifically distinct, by others as varieties; but some are certainly identical, and many, though closely related to northern forms, must be ranked as distinct species.

Now let us see what light can be thrown on the foregoing facts, on the belief, supported as it is by a large body of geological evidence, that the whole world, or a large part of it, was during the Glacial period simulta- neously much colder than at present.