ROSE GALLS. 509 



as otlier galls, but to decide upon the species which make them is 

 by no means so easy a task as appears on the surface. Even 

 should the experimenter find the right species of insect in the 

 gauze bag, he has to go through the wearisome task of searching 

 through the family of Cynipidoe, and identifying the species — a 

 process which every entomologist is rather apt to postpone until 

 the visionary period when he shall have leisure. 



But it is very probable that the required insect does not make 

 its appearance at all, and that the little hymenoptera which make 

 their way out of the cells, or are found dead within them, are not 

 the rightful occupants of the galls. For the Cynipida3 are as lia- 

 ble to parasites as other insects, and it frequently happens that 

 from a single many-chambered gall will issue insects that sadly 

 puzzle an amateur, as they seem to belong to at least two distinct 

 species. The very gall which has just been described affords a 

 good example of this fact, for in some of the chambers are speci- 

 mens of the true Cynips rosce, and in others are insects which be- 

 long to another family, the Ichneumonidas, which, as the reader 

 may remember, are parasites upon other insects. They have evi- 

 dently introduced their eggs into the cells occupied by the larvae 

 of Cynips rosce, so that the larvas which have been hatched from 

 these eggs have fed upon the legitimate occupants, and come to 

 maturity in the cells that were designed for others. 



Insects of totally different orders sometimes make their appear- 

 ance. When I began to take to pieces the gall which has been 

 described, I was rather surprised to find among the long hairs an 

 empty cocoon of the Galleria moth, whose ravages have been 

 mentioned in an earlier part of the volume. On farther dissect- 

 ing the gall, no less than twelve other cocoons were found, all 

 buried so deeply in the hairs and among the woody cells that 

 they could not be seen until the hairy clothing was removed. A 

 person who was entirely ignorant of entomology might naturally 

 fancy that the moths were the architects of the gall from which 

 they had apparently issued. How they obtained access to the 

 galls, and on what food they lived, are two problems that I can 

 by no means solve. The drawer in which the galls were placed 

 is tightly closed, and all bee, wasp, and hornet combs have been so 

 treated with corrosive sublimate that they have not been touched 

 by the caterpillars from which the moths had been developed. 



There is another gall, very common in England, which is 



