ALTERATION OF FOEM BY GALL-PRODUCING INSECTS. 



541 



several Cynipedes, e.g. Aphilotrix Sieboldi (see fig. 364 1) lay their eggs in the green 

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



(~:rj-n 



Fig. 364.— "Various Oak-galls. 



1 Solid galls on the cortex produced by Aphilothrix Sieboldi. 2 Bud-gall from, a foliage-bud produced by Cynips Hartigii. 

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

 produced by Cynips lucida. « One of these galls cut in half. 7 Leafy bud-galls produced by AphUotkrix gemmce. 

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

 on the pericarp of Quereus pubescens produced by Cynips caput-medusoB. n-i* Spangle galls on a leaf of the Turkey Oak 

 {Quercus Cerris) ; 11 produced by Neurotents lanuginosus ; 12 by Neuroterus nwmismatis ; is by Neuroterus fumipennis ; 

 14 by Spathegaster tricolor. 



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

 and Biorhiza aptera. 



