Gall-Flies. 



409 



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. 



The woolly substance on the branch of the oak which we 



Woolly Gall of the Oak, less than the natural size, caused by a Cynics, and drawn 

 from a specimen. 



have described was similarly constituted with the bedeguar 

 of the rose, with this difference, that instead of the individual 

 cells being diffused irregularly through the mass, they were 

 all arranged at the off-goings of the leaf-stalks, each cell 

 being surrounded with a covering of the vegetable wool, 

 which the stimulus of the parent egg, or its gluten, had 

 caused to grow, and from each cell a perfect fly had issued. 

 We also remarked that there were several small groups of 

 individual cells, each of which groups was contained in a 



