THE LONGEVITY OF TREES. 81 



considering it, not as a simple individual, like man or the 

 higher animals, but as an aggregate of many individuals, 

 which though ordinarily connected with the parent stock, are 

 capable of growing by themselves, and indeed often do sepa- 

 rate spontaneously, and in a variety of ways acquire indepen- 

 dent existence. If, then, the tree be, as it undeniably is, a 

 complex being, an aggregate of as many individuals, united 

 in a common trunk, as there are, or have been, buds developed 

 on its surface ; and if the component individuals be annually 

 renewed, why should not the aggregate, the tree, last indefi- 

 nitely ? To establish a proper analogy, we must not compare 

 the tree with man, but with the coral formations, in which 

 numberless individuals, engrafted and blended on a common 

 base, though capable of living when detached from the mass, 

 conspire to build up those arborescent structures so puzzling 

 to the older naturalists that they were not inappropriately 

 named " zoophytes," or animal-plants. The immense coral- 

 groves, which have thus grown up in tropical seas, have, no 

 doubt, endured for ages ; the inner and older parts consisting 

 of the untenanted cells of individuals that have long since 

 perished, while fresh structures are continually produced on 

 the surface. The individuals, indeed, perish ; but the aggre- 

 gate may endure as long as time itself. So with a tree, con- 

 sidered under this point of view. Though the wood in the 

 centre of the trunk and large branches — the produce of buds 

 and leaves that have long ago disappeared — may die and de- 

 cay ; yet while new individuals are formed upon the surface 

 with each successive crop of fresh buds, and placed in as 

 favorable communication with the soil and the air as their 

 predecessors, the aggregate tree would appear to have no 

 necessary, no inherent, limit to its existence. 1 



1 A beautiful confirmation of this view may be drawn from the cele- 

 brated Banyan, or India Fig-tree, and a few other tropical trees, which 

 freely strike root, high in the open air, from their spreading branches. 

 These aerial roots, after reaching the earth, become in time new trunks ; 

 and the whole tree appears like a huge tent, supported by many columns. 

 Milton's description of the Banyan (in " Paradise Lost ") is incorrect, 

 so far as it supposes the bending branches themselves to reach the 

 ground, and there to strike root, just as the gardener propagates shrubs 



