382 INSECT ARCHITECTURE. 



Semi-Oali of the Hawthorn, produced by Cccidomyia ? drawn from a 

 specimen. 



or rather woolly substance around the stem at the 

 origin of the leaves, which did not appear to be 

 affected in their growth, being well formed, healthy, 

 and luxuriant. We could not doubt that the woolly 

 substance was caused by some insect; but though 

 we cut out a portion of it, we could not detect any 

 egg or grub, and we therefore threw the branch 

 into a drawer, intending to keep it as a specimen, 

 whose history we might complete at some subse- 

 quent period. 



A few weeks afterwards, on opening this drawer, 

 we were surprised to see a brood of several dozens 

 of a species of gall-fly (Cynips), similar in form and 

 size to that whose eggs cause the bedeguar of the 

 rose, and differing only in being of a lighter colour, 

 tending to a yellowish brown. We have since met 

 with a figure and description of this gall in Swam- 

 merdam. We may remark that the above is not the 

 first instance which has occurred in our researches, 

 of gall insects outliving the withering of the branch 

 or leaf from which they obtain their nourishment. 



