PSEUDO-GALLS. 345 



each other, are brought close together in a bunch, forming 

 a kind of nosegay, that conceals all the colour of the sprig, 

 as well as the insects which are embowered under it, pro- 

 tecting them against the rain and the sun, and, at the same 

 time, hiding them from observation. It is only requisite, 

 however, where they have formed bowers of this description, 

 to raise the leaves, in order to see the little colony of the 

 aphides, — or the remains of those habitations which they 

 have abandoned. We have sometimes observed sprigs of 

 the lime-tree, of a thumb's thickness, portions of which re- 

 sembled spiral screws; but we could not certainly have 

 assigned the true cause for this twisting, had we not been 

 acquainted with the manner in which aphides contort the 

 young shoots of this tree.* The shoots of the gooseberry 

 and the willow are sometimes contorted in the same way, 

 but not so strikingly as the shoots of the lime. 



Shoot of the Lime-tree contorted by the punctures ot the Aphis Tilice 



Pseudo-Galls. 



It may not be out of place to mention here certain ano- 

 malous excrescences upon trees and other plants, which, 

 though they much resemble galls, are not so distinctly 

 traceable to the operations of any insect. In our researches 

 after galls, we have not unfrequently met with excrescences 



* Eeaumiu', vol. iii. 



