the olive-tree in the Citadel of Athens, or the Elm of Ephesus), the diameter of which I found, when I visited those Islands, to be more than 16 feet, had the same colossal size, when the French adventurers, the Béthencourts, conquered these gardens of the Hesperides in the beginning of the fifteenth century; yet it still flourishes, as if in perpetual youth, bearing flowers and fruit. A tropical forest of Hymenæas and Cæsalpinieæ may perhaps present to us a monument of more than a thousand years' standing.
If we embrace in one general view the different species of phænogamous plants at present contained in herbariums, the number of which may now be estimated at considerably above 80000,[13] we shall recognise in this prodigious multitude certain leading forms to which many others may be referred. In determining these leading forms or types, on the individual beauty, the distribution, and the grouping of which the physiognomy of the vegetation of a country depends, we must not follow the march of systems of botany, in which from other motives the parts chiefly regarded are the smaller organs of propagation, the flowers and the fruit; we must, on the contrary, consider solely that which by its mass stamps a peculiar character on the total impression produced, or on the aspect of the country. Among the leading forms of vegetation to which I allude, there are, indeed, some which coincide with families belonging to the "natural systems" of botanists. Such are the forms of Bananas, Palms, Casuarineæ, and Coniferæ. But the botanic systematist divides many groups which the physiognomist is obliged to unite. When plants or trees present them-
