66 



are affected, their perspiring matter becoming thick 

 and glutinous, so as to be a proper nutriment to the 

 insects, which are then always found upon them. In 

 this case the insects are not the cause, but the effect of 

 the blight. 



It is a kind of blight that produces galls, which are 

 the. buds of oaks swelled out. The cause is, into the 

 heart of the tender bud a ily thrusts one or mere eggs. 

 This egg soOn becomes a worm, and eats itself a liitlc 

 cell in the pith of the bud, which would have grown 

 into a branch : the sap, which was to nourish that 

 branch, being diverted into the remaining parts of the 

 bud, these grow large and flourishing, and becomes a 

 covering for the cell of the insect. 



Not only the willow and some other trees, but 

 plants also, nettles, ground-ivy, anil others, have such 

 cases produced upon their leaves, The parent insect) 

 with its still tail, bores the rib of the leaf when tender, 

 and makes way for her egg into the Tery pith. Pro- 

 bably she lays it there with some proper juice, to pre- 

 vent the vegetation of it. From this wound arises a 

 small excrescence, which \vhen the egg is hatched 

 grows bigger and bigger as the worm increases, swelling 

 ou each side the leaf between the two membranes. This 

 worm turns afterwards into an aurelia, and then to a> 

 small green ily. 



The Aleppo galls, wherewith we make our ink, are 

 of this number, being only cases of insects, which 

 gnawed their way out through the little holes we see hi 

 them . 



For a sample of the tender balls, see the balls as 

 round, and sometimes as big as small musket-bullets, 

 growing under oaken leaves, close, to the libs, of a 

 greenish yellowish colour. Their skin is smooth, with 

 frequent risings therein. Inwardly they are very soft 

 and spungy ; and in the very centre is a case, with a 

 white worm therein, which afterwards becomes a ily. 

 As to this gall, there is one thing need liar ; the Ily lies 

 all winter within this ball, and does not come-to ma- 

 turity till_ the following spring. In the autumn th'jse 



