ILLUSTRATIONS 



Excavating a large cavity Frontispiece 



PACING 

 PAOBJ 



Decayed maple before and after excavation ... 4 

 The same tree reinforced with rods and wire and 



filled with concrete 16 



Wounds caused by lawnmowers 26 



Wounds caused by horses gnawing the bark ... 26 



Frost-crack in black oak 34 



Oak tree with large bark wound 44 



Cross-section of maple affected by white heart-rot . 72 



Cross-section of damaged oak 72 



Fruiting bodies of white heart-rot fungus ... 80 



A tree that is not worth filling 98 



Cavity in the base of a white oak filled with concrete 114 

 Linden excavated and bolted, ready for filling . .134 



Cavity in large red maple 156 



Linden on Boston Common, treated according to the 



open system 186 



How an iron band constricts the tree 202 



Small cavity in white oak filled with concrete . . 226 

 Ash tree with large cavity correctly treated with zinc 236 



