The Story -Book of the Fields 



generations of shoots, the tree passes through 

 centuries without danger of death — at once 

 old and young, dead and alive. 



Since a ligneous layer is formed every year, 

 we need only count the number of these 

 layers to arrive at the age of the tree. So, 

 when a tree is cut across and we count one 

 hundred and fifty layers, it means that the 

 tree is one hundred and fifty years old. Let 

 us look at the transom section of some young 

 oak. From the pith to the bark there are 

 six layers, so the oak is six years old. For 

 any other tree the same calculation would 

 hold good : so many layers, so many years. 



You see, therefore, that it is very easy to 

 ascertain the age of a tree that has been cut 

 down, by merely counting the number of 

 ligneous layers in the trunk. We can also 

 do this while the tree remains standing, by 

 comparing half the diameter of the trunk with 

 the average diameter of an annual layer, 

 which is found by cutting down and examin- 

 ing a large branch. It is interesting to find 

 out the limit of age that may be reached by 

 trees. The results furnished by such observa- 

 tions will by far surpass our expectation. 

 We will confine ourselves to a small number 

 of examples of this curious subject. 



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