RENOVATION OF WOOD. 



37 



"Certain it is," says Mr. Towers, "that the bark of trees, when 

 wounded or cut in amputation of branches proceeding from the trunk, 

 converges from all points, and not solely, as some assert, from the upper- 

 most cross incision. The Elm-tree may furnish the best examples for 

 investigation, some of which are to be seen in every hedge-row. In the 

 public road leading from "Waddon to Mitcham Common, there stand 

 several large Ebns in front of a gentleman's house. A wovmd was 

 made in one of them fully eighteen inches long, and in the middle five 

 or six: wide, by which the bark stripped off to that extent, exposed the 

 wood below it. The young Uber came rolling forward on every side, 



Pig. VIII. — Closing up of an oval wound. 



and is now seen approaching pretty equally, though with projections of 

 a redder colour, which mark the more recent processes. A line of posts 

 and rails, with a chain at top, extends along the front, close to the row 

 of trees. An abrasion or wound had been made in close contact with a 

 part of the chain, which now is buried, and firmly fixed in the bark, by 

 a knotty boss formed of cortical matter." 



A striking instance of the power of reparation by mere superficial 

 increase has been recorded by the Eev. M. J. Berkeley : "A vigorous 

 Oak had been mischievously barked aU round, and to such an extent as 

 to preclude all probability of ultimate union of the severed edges. The 

 tree, however, for a year or two seemed to suffer very little from the 

 injury, as new tissue was thrown out from the exposed extremities of the 

 medullary rays ; and to such an extent, that had not the parties who 



