Figure 6. 



Oyster-shell bark-louse, — just hatched. 



See page 34. 



Figure 7. 



Oyster-shell bark-louse, — mature form. 



See page 34. 



Figure 8. 



Bridge-grafting of a girdled tree. 



See page 43. 



Figure 9. 



Saved by bridge-graftin* 



See page 43- 



