ON THE STEM OF T&EES. 345 



wood rotted in this manner, that would explain this subject The circle of 

 most evidently, and I have many drawings taken from other - m decayed 

 specimens, but too large to trouble Mr. Nicholson with ; wood, 

 but which I may at a future time make public. 



I was once fortunate enough to see a tree cut down, that Mr. Forsyth's 

 had been managed according to Mr. Forsyth's excellent me- new wood - 

 thod ; and procuring some specimens of it, the new wood had 

 begun to form in the middle, where the pith should have come, 

 but wood grew instead; and the circle of life, making a 

 large circuit, left a place in the new part for the pith. I 

 shall give a sketch from some of my drawings, as it may 

 better explain the nature of the circle of life, which after a 

 certain course returned to the place in the new wood, it 

 would have occupied in the old; as if it did not venture on 

 the fresh formed wood, till it was solid and secure. In the 

 rotten wood these vessels may be always traced by their 

 turning blacky or darkened', and in an infant plant (if the 

 seed is boiled for dissection) by their dark colour; though 

 often quite white when alive. I have now before me an 

 Anson's apricot tree, which has the extraordinary property 

 of losing one of its branches every year (I believe it is com- - 

 mon to the species). In dissecting it I find near eight inches Plants can gW& 

 dead, all but a small piece of the bark and inner bark, near t lying. 

 which has given liquid enough to form a new Jiush of leaves , 

 apparently since the wood has been entirely dead (for the 

 wood is totally void of moisture, and must have been with- 

 out life some time). This shows whence the leaves pro- 

 teed, and thaj the only nourishment they got was from the 

 carbonic acid gas they absorbed. It is true they appeared 

 languishing and ill ; still they showed fresh leaves. But it Circle of life 

 is most curious to see the struggle the circle of life has made maintain itself. 

 to maintain its existence in the injured part, and when I cut 

 it, it was wholly in the bark: but I never found any but 

 delicate fruit trees able to support such stagnations in the 

 wood, it kills our forest trees ; or at least the limb that has 

 it; though they have many other complaints, quite as bad 

 as this palsy. I never see a defective limb or branch, with- ' 

 out endeavouring to find its cause of decay by dissecting it. 

 The cherry tree is very subject to this complaint, but I know 

 no tree that better, shows the line of life, though of the 



same 



