128 
MISCELLANEOUS. 
[Part II. 
away from under the living bark. I think it 
probable that, if a new surface were veneered over 
the old scar, the stem would continue to deposit 
new growth on it from above. This tree is still 
alive,—1844, having lived, possibly, nearly forty 
years in this state. 
I imagine that the reason that this tree has 
continued to live is, that each year it has shot 
out new branches from below the scar. These 
branches have each year been eaten off by cattle ; 
but they have elaborated and returned sufficient 
sap to nourish the root, and to keep it alive. I 
imagine that, if these branches had been allowed 
to grow, they would have taken so much sap 
that it would have ceased to be forced up the 
old stem, and that the old stem would have 
died. So that, but for the annual outburst of 
shoots below the scar, the roots of the tree would 
die; and but for the annual browsing of these 
shoots, the head of the tree would die. Yet on 
this precarious tenure the tree has for so long 
held its existence. But the existence of this 
tree and of rung branches proves to ocular de¬ 
monstration that the sap goes up the heart- 
wood, since on the scar and on the rings no new 
wood or alburnum is deposited. It is true that 
the number of rings of what is called sap-ivood 
