NOTES ON THE VARIOUS SPECIES 251 



preferable to shorten in the limbs of the tree so 

 as to take some of the strain off the trunk. If 

 any work is done upon the hollow trunk it should 

 be limited to such measures as will prevent the 

 access of insects to the interior. If a tree repair 

 man advises filling a tree infested with this decay, 

 the owner should require a survey to be made of 

 the trunk, and a vertical section should be drawn, 

 showing how much of the trunk is invaded. A 

 prediction should be made, also, of the nature of 

 the incision which will be required to remove the 

 decay from the trunk, and from the roots as well, 

 if it has worked down to the base of the tree. 

 During the progress of excavation the owner 

 should see to it that the tree man has been honest 

 in his survey and thorough in his excavation. 



Healthy trees should be carefully protected 

 from fungi, which usually gain entrance through 

 dead limbs and wounds in the upper part of the 

 trunk. It is essential that sickly limbs be 

 promptly removed and that wounds be effectively 

 dressed. 



ELM 



The elm is subject to the usual quota of dis- 

 eases. One wood rot which the writer has found 

 rather common in northern Ohio he has not iden- 

 tified as any of the named fungi described by von 

 Schrenk and other writers on the diseases of trees. 



