250 GROWTH AND LONGEVITY OF TREES. 



w,oody matter, which is pressed out towards the circumference. By the con- 

 tinuance of this process, the stem becomes so compressed that it is not capable of 

 any further compression. Thus there is no space left for the introduction of new 

 woody matter from the leaves. The consequence is, that the full action of the 

 functions of the leaves is prevented. The tree, therefore, perishes, because its 

 vitality is dependent upon the full action of all its parts. Trees belonging to this 

 class cannot exist beyond a definite period, which is seldom found to exceed 200 

 or 300 years. 



The other class of trees increase principally in length, when young. They 

 afterwards extend in diameter by means of longitudinal fibres being insin- 

 uated by the leaves under the bark, on the outside of the wood. The bark 

 being capable of indefinite extension, it is evident that nothing independent of 

 accident can put an end to the existence of such trees. Eminent botanists see 

 nothing unplausible, and no one can point out anything impossible, in the idea 

 that some trees of this kind at present existing may have been spectators of 

 the flood. 



The age of trees belonging to this class can be ascertained by counting the 

 number of rings into which they are divided. Every one of these rings must 

 have been produced in neither more nor less than a year ; and this is the ground 

 upon which botanists have arrived at such precise conclusions concerning the 

 longevity of some trees. We shall notice the ages of a few ascertained in 

 this manner. 



Decandolle mentions an Elm 335 years old; a Cypress, about 350; a 

 Cheirostemon^ about 400; an Ivy, 450 ; a Larch, 576 ; an Orange-tree, 530; 

 an Olive-tree, 700.; an oriental Plane, ?20 ; a Cedar of Lebanon, about 800; 

 Oaks, 870, 1,080, and 1,500; Limes, 1,076, and 1,147; Yews, 1,214, 1458, 

 2,280, and 2,588 ! 



At Ellerslie, the birth place of Wallace, near Paisley, there is an Oak-tree 

 which is said to have concealed under its branches Wallace and 300 of his 

 followers. However doubtful this may be, it is certain that " the Wallace 

 'Oak" cannot be much less than 700 years old. 



Eight Olive-trees still grow in the garden at Gethsemane, near Jerusalem, 

 "which can be proved to have been there more than 800 years ago, and which are 

 alleged to have been witnesses of the Saviour's agony. 



Such great antiquity, however, is small when compared to the age of the Baobab, 

 some specimens of which, growing in Africa, Adanson found to be 5,000 years 

 old ! Even this great age is surpassed by that assigned to the Taxodium by 

 Decandolle, who makes some specimens -which he discovered in South America 

 to be 5,840 years old ! Adanson ascertained some Banian trees to be of equal 

 antiquity. 



