ALTERATION OF FORM BY GALL-PRODUCING INSECTS. 



541 



several Cynipecles, e.g. Aphilotrix Sieholdi (see fig. 364^) lay their eggs in the green 

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



1 Solid galls on the cortex produced by Aphilothri. SieMd. ^ Bud-gall from a foliage-bud Pf-'-^'J/^.f;;;;'!;* "^^S 

 8 Solid oralis on an Oak twi- produced by Cynips Kollari. * One of these galls cut m half. ' Bud-gnlls f. on. foliafee-buds 

 pro^dLtT by C^^^i'Sl' e one of' th'ese'galls cut in half. ^ Leafy ^^^'f!^^^ ^^l^'J^^^'X''^^ 

 8 Bud-galls from foliage-buds produced by Cynips polycera. ^ Long.tiul.na section through c.,e ° "^^^ ^"J^ . J*J 

 on the pericarp of Querc«s pubescens produced by Cynips caput-med,u^ n-u Spangle gal on '."/?'; ''^;;,'';j„^'' 

 (Quercus Cerns); u produced \,y Neuroterus lanuginosus; « by Heurotencs numumatu: » b> >cu,.tern> /u,nn^nnu, 

 11 by Spathegaster tricolor. 



in this situation in the oak, being produced by the gall-wasps ApldlothrLv rudicis 

 and Biorhiza aptera. 



