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MODIFICATIONS OF GALL-GIIOWTH. 

 Bv Edward A. Fitch. 



In the April number of the 'Entomologist' (Entom. xi. 82) 

 attention was called to the little-understood subject of gall- 

 growth and gall-structure b}' a consideration of two or three 

 abnormal forms. The perusal of that interesting paper has 

 suggested to me that it may not be untimely to call attention 

 to various other modifications. Not the modifications and 

 monstrosities occasioned through injury or wounds to the 

 gall itself; neither those resulting from its position as to 

 surrounding growths and objects, nor those which may be 

 attributed to suppressed or stimulated growth. With these 

 external developments, of each of which many curious forms 

 could be instanced, the causes are, to a certain extent, 

 explicable by the scientific or observant botanist, but with 

 the modifications that are due to internal influences the case 

 is different; and it is to these — to such as are occasioned by 

 the life within the gall itself — that I wish to direct attention. 



In order to make my subject clear, and limit mj' observa- 

 tions, I shall confine myself specially to the well-known galls 

 of two species of Cynipicla, viz. — Ci/nips Kollari (the 

 common Devonshire, or marble, gall of the oak) and 

 Rhodites eglanler'KB (the globular gall of the rose leaf). 



Before treating of these, and to serve as a preface to my 

 remarks, I may refer to two instances of abnormal tenancy in 

 galls, — first that of an Atidrtcus, then the common history of 

 those frequent lodgers the Syiwryi. A common gall, occurring 

 on oak-buds, is that of Aphilotlirix yennnoi, which is generall}' 

 known as the artichoke gall. It consists of a cupule, to which 

 the more or less modified leafy scales are attached, with a 

 peduncular oviform inner gall. The normal section is as at 

 fig. 1 ; within the central inner gall the larva of the gall- 

 uiaker lives. This inner gall is greatly modified by immaturely 



