98 



girthing of any sound timber I have ever 

 measured, though probably the pollards 

 never girthed large as sound trees. Even 

 when the circle is broken, and they stand 

 like detached strips of bark, the new 

 deposit of wood and bark takes place on 

 their outside, while their inside is slough- 

 ing or rotting off ; and these detached 

 strips gradually, and annually, progress 

 outwards from what was the centre of the 

 tree. 



Of course, all side or lateral growth is, 

 from the position of its weight, more liable 

 to break than upright or vertical growth. 

 When a tree takes two leaders, from want 

 of light and from want of room on the 

 inside, the leaders grow from one another 

 to the outside, and from their weight 

 inclining to the outside, without any thing 

 to balance it on the inside, they are liable 

 to split from one another. As each leader 

 enlarges annually in diameter, the junction 

 at their two bases progresses upwards, en- 



