TREE PLANTING ON STREETS AND HIGHWAYS. 193 



gent methods and faithful work control the evil as far as possible. The potato bug 

 was a formidable enemy at one time ; but the farmers kept on planting and fighting 

 until they succeeded in overcoming or controlling it. It has been demonstrated that 

 by spraying trees, by using suitable emulsions and insecticides, and by gathering the 

 cocoons the destructive work of insects can, for the most part, be prevented or, at 

 least, controlled. The State Entomologist is ready at all times to furnish informa- 

 tion and advice to any who need his assistance. With proper care and attention 

 the trees can be protected ; but, if this care and attention will not be given, the 

 selection of the tree is of little importance. 



Rapidity of (irovtl). 



Trees have been described here as of rapid growth and slow growth. These are 

 largely relative terms which, to some people, may convey but little meaning. They 

 will be better understood when the growth rate of some of our well-known species 

 is noted. Beginning with a three-inch sapling, the following named trees will, in 

 twenty years, under favorable conditions, attain a diameter approximately as follows : 



White or Silver Maple, - 21 inches 



American Elm, I 9*' 



Sycamore or Buttonball, 18" 



Tulip Tree, 18 " 



Basswood, - - 17" 



Catalpa (spea'osa), 16" 



Red Maple, 16 " 



Ailanthus, 16" 



Cucumber Tree, '5" 



Chestnut, T 4 " 



Yellow Locust, 14" 



Hard Maple, 13 " 



Horse Chestnut (hippocastanutn), 13 " 



Honey Locust, --------- 13" 



Red Oak, 13 " 



Pin Oak, , 13 " 



Scarlet Oak, 13 " 



White Ash, 12 " 



White Oak, 11 " 



Hackberry, 10" 



The height which each species may be expected to attain is omitted here, as it 



will assume the usual proportion to the diameter. 

 '3 



