I have also endeavoured to establish the number of centuries or thousands of years during which each species has been in cultivation, and how its culture spread in different directions at successive epochs.
A few plants cultivated for more than two thousand years, and even some others, are not now known in a spontaneous, that is, wild condition, or at any rate this condition is not proved. Questions of this nature are subtle. They, like the distinction of species, require much research in books and in herbaria. I have even been obliged to appeal to the courtesy of travellers or botanists in all parts of the world to obtain recent information. I shall mention these in each case with the expression of my grateful thanks.
In spite of these records, and of all my researches, there still remain several species which are unknown wild. In the cases where these come from regions not completely explored by botanists, or where they belong to genera as yet insufficiently studied, there is hope that the wild plant may be one day discovered. But this hope is fallacious in the case of well-known species and countries. We are here led to form one of two hypotheses; either these plants have since history began so changed in form in their wild as well as in their cultivated condition that they are no longer recognized as belonging to the same species, or they are extinct species. The lentil, the chick-pea, probably no longer exist in nature; and other species, as wheat, maize, the broad bean, carthamine, very rarely found wild, appear to be in course of extinction. The number of cultivated plants with which I am here concerned being two hundred and forty-nine, the three, four, or five species, extinct or nearly extinct, is a large proportion, representing a thousand species, out of the whole number of phanerogams. This destruction of forms must have taken place during the short period of a few hundred centuries, on continents where they might have spread, and under circumstances which are commonly considered unvarying. This shows how the history of cultivated plants is allied to the most important problems of the general history of organized beings.
Geneva, 1882.
CONTENTS.
| PART I. | ||
| GENERAL REMARKS. | ||
| chapter | page | |
| I. | In what Manner and at what Epochs Cultivation beganin Different Countries | [1] |
| II. | Methods for discovering or proving the Origin of Species | [8] |
| PART II. | ||
ON THE STUDY OF SPECIES, CONSIDERED AS TO THEIRORIGIN, THEIR EARLY CULTIVATION, AND THEPRINCIPAL FACTS OF THEIR DIFFUSION. | ||
| I. | Plants cultivated for their Subterranean Parts, suchas Roots, Tubercles, or Bulbs | [29] |
| II. | Plants cultivated for their Stems or Leaves | [83] |
| III. | Plants cultivated for their Flowers, or for the Organswhich envelop them | [161] |
| IV. | Plants cultivated for their Fruits | [168] |
| V. | Plants cultivated for their Seeds | [313] |
| PART III. | ||
| SUMMARY AND CONCLUSION. | ||
| I. | General Table of Species, with their Origin and theEpoch of their Earliest Cultivation | [436] |
| II. | General Observations and Conclusions | [447] |
| Index | [463] | |