We might add considerably to this list, but it already supplies a sufficient number of illustrations of our general remarks.

Years

Palms of .....

200,300

Cereis.....

300

Cherodenlron

327

Ulnus (Elm)...

365

Cupressis (Cypress)...

389

Hedern (Ivy)...

449

Acer (Maple)...

516

Lurix (Larcis)...

263,576

Years

Castanea (Chestnut).....

360,626

Citrus (Lemon,Orange,

&c).......400,500,610

Plantanus (Plane)....

720

Cedrus (Cedar)....

200,800

Juglans (Walnut)....

900

Tilin (Lime) 364,530,800,825,1036

Abies (Spruce).....

120

Years.

Quercus (Oak) 600,800,860,1000,

1600

Oea (Olive)....

700,1000,2000

Taxus (Yew) 1214,1466,2588,2860

Schubertin (Taxodium)....

3000,4000

Leguminosoea....

2652,4101

Adnusonia (Baobab)....

6000

Dracaena (Dragon Tree)...

6000

The moans, by which the age of these trees has been ascertained, are two - first, from historical data, and second, from counting the zones. Thus, the colossal Dragon-tree of Oratava is known to have existed, in almost its present condition, in 1402; and comparing it with the younger trees in its neighborhood, its vast age is inferred. The Yew trees at Fountain's Abbey, in Yorkshire, are known to hare sheltered the monks whilst the abbey was building. The abbey is now in ruins, but the trees retain their vigor; the lowest age that can be assigned them is twelve centuries; they are probably much more. But where trees have been cut down, the method of counting the zones has been had recourse to.

[The accompanying engravings, representing sections of Exogen and Endogon, will explain themselves. The number of zones in trees will probably give a tolerable approximation to the years of growth in temperate climates; but even here, two may be formed in one year, if any great check of the growth suddenly occurs during the summer. In tropical climates the indication is for more doubtful; Adanson's computation, made in this way, carried the ago of the Baobabs to from 5000 to 6000 years. It has been stated that monthly rings are formed in the tropics of South America, (Hopkins' Researches in Magnetism.) . Some plants, such as the Cacti and Cycadoae, require more than one year for the formation of a zone of wood.]