VOLUME AND YIELD. 33 



is often seriously damaged -by various kinds of wood-boring beetles 

 and larva?. The sapwood of all kinds of hickory wood products, even 

 after seasoning, is subject to great damage by various species of 

 powder post insects. In short, insect injury has contributed greatly 

 to waste in hickory, and has reduced revenues and profits. Practical 

 methods of preventing losses from these insects have been determined 

 and may be adopted and successfully carried out at slight expense. 



A very serious defect of hickory trees is " cup-shake." This occurs 

 commonly in the heartwood of mature trees in those portions where 

 the growth has been very slow, and consequently a number of open 

 porous layers come together. It is most common where the porosity 

 of the wood is increased by a large amount of moisture in the soil, 

 and therefore most likely to occur in southern hickory. There are 

 two ways by which loss from this source can be entirely avoided, 

 first, by keeping the trees growing steadily, so that no succession of 

 narrow rings will be formed, and, second, by cutting them before they 

 reach large size. 



Young hickories are very susceptible to frost. Out in the open, 

 without protection from an older stand, they are apt to be killed back 

 by frost, and this forms one of the chief objections to growing hickory 

 in plantations in the northern part of its range; it has proved an 

 obstacle to the introduction of the hickories into Germany, where big 

 shellbark and mockernut are too sensitive to grow successfully. 

 Bitternut, pignut, and shagbark are unquestionably the least sus- 

 ceptible to frost and pecan and water hickory the most. 



A source of considerable injury in some places is the practice of 

 bumping or striking against the trunks of young shagbarks or big 

 shellbarks with a heavy object or a long pole to shake down the nuts 

 in the fall. It causes serious defects, if not actual decay in the wood. 



VOLUME AND YIELD. 

 VOLUME. 



One of the first things which a practical lumberman wants to know 

 about a tree is how much merchantable lumber it contains and what 

 is its quality ; he usually answers this by estimating the product which 

 may be obtained from it. By long years of experience he becomes 

 very skillful in thus determining the contents of a tree. In buying and 

 selling stumpage it is essential to determine the volume of single trees, 

 for by the estimates of individual trees the value of the stand is 

 determined. 



To determine the value of a particular tree, the most satisfactory 

 method is to estimate the number and size of the logs which it con- 



For specific information about the insects injurious to hickory or other forest 

 trees, inquiries should be made directly to the Bureau of Entomology, U. S. Depart- 

 ment of Agriculture, and, whenever possible, specimens of the insects and of their 

 work should be submitted. 



