→ was included within 1859 1860 1861 |
formed part of 1866 |
|
→ long 1859 1860 |
a long time 1861 1866 |
|
→ between 1859 1860 1861 1866 |
besides many closely allied species, between 1869 1872 |
|
→ Europe, 1859 1860 1861 1866 |
North America and Europe, 1869 1872 |
|
→ two points are; and there are many closely allied species. 1859 1860 1861 1866 |
areas in opposite hemispheres are from each other. 1869 1872 |
|
→ European 1859 1860 1861 1866 |
temperate European, some Antarctic, and some Andean 1869 1872 |
|
→ genera 1859 1860 1861 1869 1872 |
temperate, some antarctic, and some Andean genera 1866 |
|
sides of the world. But we have good evidence in almost every case, that the epoch
→was included within
the latest geological period. We have, also, excellent evidence, that it endured for an enormous time, as measured by years, at each point. The cold may have come on, or have ceased, earlier at one point of the globe than at another,
seeing that it endured for
→long
at each, and that it was contemporaneous in a geological sense, it seems
probable that it was, during a part at least of the period, actually simultaneous throughout the world. Without some distinct evidence to the contrary, we may at least admit as probable that the glacial action was simultaneous on the eastern and western sides of North America, in the Cordillera under the
warmer temperate zones, and on both sides of the southern
of the continent. If this be admitted, it is difficult to avoid believing that the temperature of the whole world was at this period simultaneously cooler. But it would suffice for my purpose, if the temperature
at the same time lower along certain broad belts of longitude. |
|
On this view of the whole world, or at least of broad longitudinal belts, having been simultaneously colder from pole to pole, much light can be thrown on the present distribution of identical and allied species. In
Dr. Hooker has shown that
→between
forty and fifty of the flowering plants of Tierra del Fuego, forming no inconsiderable part of its scanty flora, are common to
→Europe,
enormously remote as these
→two points are; and there are many closely allied species. On the lofty mountains of equatorial America a host of peculiar species belonging to European genera occur. On the
mountains of Brazil, some few
→European
→genera
were found by Gardner, which do not exist in the
|