BRITISH GALL-INSECTS. 6 



this country. Siit experience has shown to me, that it is 

 sometimes positively against the interests of science, to trust 

 too much to the lines of investigation laid down by others, 

 and I would therefore earnestly entreat all such, as have the 

 leisure, to examine again for themselves whatever plants 

 come under their notice, and if they should meet with any 

 excrescence unknown to themselves, to communicate forth- 

 with with me on the subject. I always prefer to examine 

 well-known objects over again, than run the risk of missing 

 a novelty. Already I possess materials for a further list of 

 gall-bearing British plants, which is still receiving con- 

 tinuous additions. 



The following orders of insects furnish gall-makers: — 



1. Hymenoptera. 



a. Cynij^idce. 



b. Tentlireclinidce (saw-flies). 



c. Clialcididce (^Isosomci). 



2. DiPTERA. 



a. Cecidomjjidce (gall-midges). 



b. Mycetophilidce. 



c. Trypetid(B. 



d. Agromyzidce, (Query ? if any British gall- 



makers are known.) 



3. COLEOPTERA. 



a. Curcullonidce (gall-weevils). 



b. Sagridce (exotic only). 



c. Lamiadce. 



4. HoMOPTERA and Heteroptera. 



a. Aphides. 



b. Psyllidce. \ No gall-makers known to me in 



c. Coccklcv. > Britain at present, although the 



d. Tlngidce. ) P.sj/Z/iVZ*^ are sure to produce some. 



b2 



