11 Nov., 1918.] 



Apple Culture in Victoria. 



651 



circumscribes the wood formed during the fifth year of the tree's growth, 

 and (a) denotes the point at which the gnarl commenced when the 

 tree was three years old. The next circle shows the extent to which 

 development would have taken place under normal growth, and defines 

 the course of the gnarling during that time. The outer circle only shows 

 approximately the diameter of the stem, because the full action of the 



Plate 180. — A limb from a badly-affected two-year old Gravenstein tree. 



sap in any particular sector, while blocked in others, causes the forma- 

 tion of thicker layers of wood in that direction. Hence the diameter of 

 this circle is proportionately greater than it would be had natural 

 development taken place. The inner circle in Fig, 2 shows the dia- 

 meter reached by the wood rings of this section at the end of the 

 eighth year, and the indentations denote that the gnarling commenced 



