After felling wood is 'washed' by placing in flowing rivers. This washes out all the sap and when dried makes the wood more stable. The drying process takes place in kilns after the tree has been converted into workable sizes. All woods are prone to attack by fungus which often occurs if wood is damp. All woods are prone to attack by insects which lay eggs in cracks and the resulting lava eat the wood. Some examples of these insects are given below.

1. Roots - absorb water & minerals & support the tree.
   
2. Sapwood - new wood which carries water and minerals to leaves ready for conversion into food.
   
3. Heartwood - once sapwood but now inactive giving support to the tree, the wood used for making things.
   
4. Pith - centre of tree and remains of earliest growth.
   
5. Medullary rays - look like spokes of a wheel and carry waste to be stored in mature cells.
   
6. Leaves - convert water and minerals into food that the tree can use (photosynthesis).
   
7. Bark - protects tree from damage, extremes of temperature and prevents water loss.
   
8. Bast - carries the food.
   
9. Cambium layer - where growth by cell division takes place.
   
10. Annual rings - growth rings (two per year, a thick one for summer and a thin one for winter.