ALTERATION OF FORM BY GALL-PRODUCING INSECTS. 



541 



several Cynipedes, e.g. Aphilotrix Sieboldi (see fig. 364 a ) lay their eggs in the green 

 cortex of the young twigs. Solid galls are very rare on roots, but they do occur 



Fig. 364. Various Oak-galls. 



i Solid galls on the cortex produced by Aphttothrix SieboldL Bud-gall from a foliage-bud produced by CympsHart^. 

 Solid galls on an Oak twig produced by Cynips Kollari. * One of these galls cut in half. * Bud-galls from foliage-buds 

 produced by Cynips lucidl. 6 One of these galls cut in half. T Leafy bud-galls produced by AphUothrrx gemma, 

 8 Bud-galls from foliage-buds produced by Cynips polycera. Longitudinal section through one of these galls. 10 Gall 

 on the pericarp of Qufrcus pubescens produced by Cynips caput-medusce. n-u Spangle gaUs on a leaf of the Turkey Oak 

 (Quercus Cerris) ; "produced by Neuroterus lanuginosus ; u by Neuroteru* numismatis ; by Ncuroterus /unupennw ; 

 " by Spathegaster tricolor. 



in this situation in the oak, being produced by the gall-wasps Aphilothrix radicis 

 and Biorhiza aptera. 



