M. de Humboldt's View of the various Productions of the different Countries of the Earth.

[Personal Narrative.]

Every hemisphere produces plants of a different species; and it is not by the diversity of climates that we can attempt to explain why equinoctial Africa has no laurineae, and the New World no heaths; why the calceolariae are found only in the Southern hemisphere; why the birds of the continent of India glow with colours less splendid than the birds of the hot parts of America; finally, why the tiger is peculiar to Asia, and the ornithorhincus to New Holland.

In the vegetable, as well as in the animal kingdom, the causes of the distribution of the species are among the number of mysteries which natural philosophy cannot reach.

This science is not occupied in the investigation of the origin of beings, but of the laws according to which they are distributed on the globe. It examines the things that are, the coexistence of vegetable and animal forms, in each latitude, at different heights, and at different degrees of temperature; it studies the relations under which particular organizations are more vigorously developed, multiplied or modified; but it approaches not problems, the solution of which is impossible, since they touch the origin, the first existence of a germ of life.

We may add, that the attempts that have been made to explain the distribution of various species on the globe, by the sole influence of climate, date at a period when physical geography was still in its infancy; when, recurring incessantly to pretended contrasts between the two worlds, it was imagined, that the whole of Africa and of America resembled the deserts of Egypt, and the marshes of Cayenne.

At present, when men judge of the state of things not from one type arbitrarily chosen, but from positive knowledge, it is ascertained that the two continents, in their immense extent, contain countries that are altogether analogous.

There are regions of America, as barren and burning as the interior of Africa.

The islands that produce the spices of India are scarcely remarkable for their dryness; and it is not on account of the humidity of the climate, as it has been affirmed in recent works, that the New Continent is deprived of those fine species of laurineae and myristicae, which are found united in one little corner of the earth, in the archipelago of India.

For some years past, the real cinnamon has been cultivated with success in several parts of the New Continent; and a zone that produces the coumarouna, the vanilla, the pucheri, the pine-apple, the myrtus pimenta, the balsam of tolu, the myroxylon peruvianum, the crotons, the citrosmas, the pejoa, the incienso of the silla of Caraccas, the quereme, the pancratium, and so many majestic liliaceous plants, cannot be considered as destitute of aromatics.

Besides, a dry air favours the developement of the aromatic, or exciting properties, only in certain species of plants.

The most cruel poisons are produced in the most humid zone of America: and it is precisely under the influence of the long rains of the tropics that the American pimento, capsicum baccatum, the fruit of which is often as caustic and fiery as Indian pepper, vegetates best.

From the whole of these considerations, it follows, 1st, that the new continent possesses spices, aromatics, and very active vegetable poisons that are peculiar to itself, differing specifically from those of the ancient world; 2dly, that the primitive distribution of species in the torrid zone cannot be explained by the influence of climate solely, or by the distribution of temperature, which we observe in the present state of our planet; but that this difference of climate leads us to perceive, why a given type of organization developes itself more vigorously in such or such local circumstances.

We can conceive, that a small number of the families of plants, for instance the musaceae and the palms, cannot belong to very cold regions, on account of their internal structure and the importance of certain organs; but we cannot explain why no one of the family of melastomas vegetates north of the parallel of thirty degrees, or why no rose tree belongs to the southern hemisphere.

Analogy of climates is often found in the two continents, without identity of productions.--Personal Narrative, vol. v. p. 180.