410 TRANSACTIONS AND PKOCEEDINGS 01'" THI': [Sess. Lxvii. 



taken from the circumference of the Cowthorpe Oak itself, 

 and the rings measured with a view of arriving at the annual 

 increment of the tree throughout its life, this method would 

 be quite as fallacious, for trees when they are young grow 

 much faster than when they are old. 



Whilst considering the photograph (No. 6) of the section, 

 let us see whether it supports or opposes De Candolle's 

 theory of indefinite longevity of trees. From the centre to 

 No. 1 there are 100 annual rings of growth. From No. 1 

 to No. 2 there are 50 rings. From No. 2 to No. 3 

 there are 20 rings, and from No. 3 to the circumference 

 there are 42 rings. That is, for one hundred and fifty 

 years, or to No. 2, the tree had increased upon the 

 whole in a uniform degree, but during the next twenty 

 years the growth slowed down to less than half as much, 

 and the last forty-two years of its existence it had slowed 

 down still more, so that there was hardly any growth at 

 all. This decadence in growth during the latter years is 

 said to be only apparent, and not real. For, during the latter 

 years, the tree is said to be so much bigger than what it 

 was formerly, that though the annual layer of growth which 

 covers the whole tree is thinner, the extended area of the 

 surface of the enlarged tree is so much more as to account 

 for the difference in the thickness of the annual growth. 

 This explanation might be convincing in the absence of the 

 photograph, but with the photograph before us it is not, 

 for that plainly indicates that the thickness of the annual 

 growth was nearly uniform to the time when the tree would 

 be one hundred and fifty years old, notwithstanding that 

 during all those years the surface of the tree would be annually 

 enlarging. Therefore the lessening of the thickness of the 

 annual growth in the latter years is distinctly different to 

 what had happened during the one hundred and fifty years 

 before, and it is a natural decadence which had come with 

 years, that pointed as certainly to death from old age, as 

 it flatly contradicted the theory of indefinite longevity of 

 trees. 



If we could have watched this tree during all the two 

 hundred and twelve years of its life, we should have seen 

 it grow in height and spread of branches till perhaps it 

 was seventy to one hundred years of age. Then for fifty 



