1 82 TK.LXSFO/^MATIOXS OF IXSECTS. 



The large engraving shows the galls of the msect. They are 

 cellular, and are aggregated in masses upon the twigs. 



A very common species of Cynips — Cynips aptcra — produces 

 great galls upon the roots of the oak, and it is a most remarkable 

 thing that neither the males nor the females should have wings. 



The gall nuts of commerce, which are used as dyes, and to 

 make ink and tinctures, and whence gallic acid is derived, are 

 produced by the punctures of Cynips gallce tinctorics. These 

 insects affect an Eastern species of oak, Querais infcctoria, and 

 their galls are remarkably hard, round, and tuberculated. They 



Female. Male. 



Cynips trrmiiialis, 



only contain one larva. The cellule is moderately capacious, but 

 the walls are very thick ; nevertheless, the little Cynips perforates 

 them without much difficulty, in order to come to the light of 

 day. 



The rose fungus is one of the most curious galls ; it is pro- 

 duced by a Cynips, and is found upon the hedge roses and sweet- 

 briars. The adult insect which produces these excrescences is 

 about the fifth of an inch long. Its transparent wings are 

 slightly clouded, and it is of a glossy black colour. The females 

 lay their eggs towards the end of May or the beginning of June, 

 and the galls soon form, but they grow at first very slowly, and 

 subsequently quickly, so that they attain their full size on the 

 approach of cold weather. Sometimes the galls are round, or 

 flat, at others they are irregular in shape, and resemble medlars, 

 and they are about the same size as those fruits. They are 



