the Miocene, covered with magnificent forests of magnolias, oaks, cypresses, and a hundred other species. In more remote periods they abounded in plants and animals, whose fellows of identical species lived at the same time,[1] or at least in the same geological period, near the equator.
These statements are so extraordinary that they need to be established by unanswerable evidence. Of this there is a great abundance.
In latitude 81° 40' Captain Nares found the remains of corals in vast quantities. These creatures require not merely a warm but an equable temperature. Those of to-day can not live where the temperature falls below 66° Fahr. Sir Charles Lyell says: "The same genera, and to some extent the same species, of Ammonites are found in those high latitudes and in India. Remains of a large ichthyosaurus were brought by Sir Edward Belcher from latitude 77° 16'. Others were found by the Swedish expedition in Spitzbergen, latitude 78° 10'." In Dana's "Manual of Geology," under the heading "Climate," in all the early periods, abundant illustration is given of the uniformity of climate in high and in low latitudes. On page 181 he sums up in these words: "No marked difference between the life of the primordial period in warm and cold latitudes has been observed"; and again, on page 253, "The living species, from 30° to 80°, were in part the same, or closely allied."
It is unnecessary to multiply proofs. All geologists agree that, all over the world, the plants and animals of any particular horizon were exceedingly alike, and very often identical. The living species to which they are most nearly allied are peculiarly sensible to changes of temperature.
So far, therefore, as it is possible to judge the past by the present, the fossils indicate a warm and uniform temperature almost to the poles, such as is now found in regions inhabited by similar species. Geologists are forced to this conclusion. In that wonderful work, Professor Dana's "Manual of Geology," it crops out everywhere: Page 266, "There is no sufficient evidence of cold arctic seas"; page 289, "There was little difference of temperature between temperate and arctic seas." (See pages 352, 452, 480, 488, 514, 521, 526, etc.) All tell the same story. "No zones of climate." Warm arctic seas all the year round.
It may, however, be thought that no very certain conclusions can be drawn from these facts, because the identical species which flourished in those remote times are no longer extant, and perhaps they
- ↑ It is of small importance, in reference to these questions, whether Huxley's "Homotaxy" is true or not. If true, then these same species lived first in high latitudes, and afterward in low, or vice versa. The important point for my present inquiry is, that the same species lived and flourished in places where life-conditions now are so extremely unlike.
