PLATE XXIX. An open allee 12 feet wide and 800 feet long, developed 

 by the use of white birch planted 3 to 4 feet apart in each row. Fora per- 

 manent allee of this type the birch is not ideal because of its short-lived 

 characteristics and susceptibility to borer. Thorns, or the European beech 

 would be preferable. (See page 147, group XVI-D-b-i) 



