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the wood beneath the burrow and causing the bark above it to crack. 
The accidental joining of a number of these galleries may girdle the 
tree, which then dies. When only a few larvae infest it each year the 
tree dies gradually, the area available for the supply of sap being 
reduced from season to season. Dr. Smith has found that vigorous 
trees like the Kieffer will repair damages for some time, but that even 
Fig. 26. — Work of Agrilus smvatvs in bark of pear: about one sixth natnral size. (After Smith.) 
these succumb at last. The excellent illustration of the work of this 
destructive larva, which we present ( Fig. 26), has been loaned us by Dr. 
Smith, and is reproduced from a photograph of a Seckel pear rice at 
the point of branching, the bark being removed from the trunk and 
one of the branches to show the galleries. This tree, he says, was 
