THE WILLOW. 



257 



tip of one wing to that of the other. Its prevail- 

 ing colour is grey, crossed with countless brown 

 lines, of which two 

 broader stripes towards 

 the outer border are par- 

 ticularly conspicuous. 



As a great number 

 of caterpillars frequently 

 attack the same tree, the 

 ravages which they com- 

 mit are very considerable. 

 Not only is the timber 

 spoiled, but in the course 

 of a few years so much 

 of the trunk is destroyed 

 that the tree is very 

 liable to be blown down, 

 even in a moderate gale. 

 The Elm, Walnut, and 

 other trees are also sub- 

 ject to the attacks of 

 these mischievous insects. 

 The reader is referred to 

 the authors above men- 

 tioned for a description 

 of other insects, which, 

 in the larva state, feed 

 on the Willow. 



The Willow is liable to 

 the attacks of a Gall-fly, 

 which, in the summer, 

 lays its eggs in the young 

 twigs. The effect is that 

 the juices of the tree, diverted from their natural 

 use, harden into an irregular mass, which, when 



II. s 



WILLOW GALL. 



