The More We Study The Distribution Of Organized Beings On The Globe, The More We Are Inclined, If Not To Abandon The Ideas Of Migration, At Least To Consider Them As Hypotheses Not Entirely Satisfactory.

The chain of the Andes divides the whole of South America into two unequal longitudinal parts.

At the foot of this chain, on the east and west, we found a great number of plants specifically the same. The various passages of the Cordilleras nowhere permit the vegetable productions of the warm regions to proceed from the coasts of the Pacific to the banks of the Amazon. When a peak attains a great elevation, either in the middle of very low mountains and plains, or in the centre of an archipelago heaved up by volcanic fires, its summit is covered with alpine plants, many of which are again found, at immense distances, on other mountains having an analogous climate. Such are the general phenomena of the distribution of plants.

It is now said that a mountain is high enough to enter into the limits of the rhododendrons and the befarias, as it has long been said that such a mountain reached the limit of perpetual snow. In using this expression, it is tacitly admitted, that under the influence of certain temperatures, certain vegetable forms must necessarily be developed. Such a supposition, however, taken in all its generality, is not strictly accurate. The pines of Mexico are wanting on the Cordilleras of Peru. The Silla of Caracas is not covered with the oaks which flourish in New Grenada at the same height.

Enter page number Go  Previous Next
Page 660 of 779
Words from 179378 to 179642 of 211363