162 THE BOOK OF FORESTRY 
habit of sending its roots into drains and sewers in 
search of water- with the result that the sewage is 
forced back into the house. In many cities the plant- 
ing of poplars in the streets has been forbidden by law. 
Box Elder.—The box elder is likely to be ill-shapen 
and to suffer greatly from insect attacks. 
Catalpa.—The catalpa is objectionable on account of 
the litter it drops. 
Horse Chestnut.—This tree also litters the ground 
beneath and is quite likely to become a menace 10 
passers by on account of its tendency to split and 
break. Practically all fast-growing trees are short- 
lived and are apt to be brittle. Such trees may be used 
for special purposes but should be followed by more 
desirable individuals. 
American Elm and Hard Maple—Certain trees like 
the American elm and hard maple are beautiful shade 
trees but on account of insect enemies should not be 
planted in certain regions. Throughout southern New 
England the elm can hardly be kept alive without one or 
two sprayings each spring with lead arsenate to kill the 
elm leaf beetle, while the frequent attacks of the maple 
borer make many beautiful round-headed sugar maples 
unsightly in a very short time. The use of such trees 
must depend upon local conditions. 
Norway Maple and Plane Tree—One of the most 
popular trees for street planting today is the Norway 
maple. It is a compact tree with round dense crown 
having foliage that 1s a dark rich green. It is com- 
paratively free from attack. Another desirable tree is 
the Oriental sycamore or plane tree. Not only is it a 
rapid grower but it is comparatively long-lived which 
makes it one of the best for street planting. Such 
trees as the Huropean linden and certain of the oaks— 
