ACORN- AND BUU-UALLS OF QUERCUS CKRRIS. 'JOS 



The acorn-galls of the two trees differ slightly in ihe 

 individual cells of the aggregate gall, being rather more 

 unmeroiis and more irregularly placed in that of the Turkey 

 oak than of its sub-variety ; but I do not see any essential 

 difference between them. In each instance the gall-mass 

 occupies the whole of the inside of the stunted acorn, and is 

 formed of an aggregation of cells, occasionally separable, 

 but more commonly firmly grown together, this mass being 

 brown outside from the adherence of the outer pellicle of the 

 acorn, and either smooth or irregidarly lobed, or with regular 

 lobes running from end to end, according to the more or less 

 regular disposition of the cells. These cells are single 

 chambered, with hard woody walls, and smooth light- 

 coloured interior. 



On February 18th I found a few of these gall- deformed 

 acorns, which had fallen from their shells, and had the cells 

 empty and apparently recently perforated, beneath one of 

 the old trees of Quercns cerris, at Kew ; one specimen, with 

 undeveloped larvae in the cells, alone remaining in its acorn- 

 shell and cup. The galls in this case were all about a 

 quarter of an inch or more in diameter, formed of from about 

 seven to ten cells ; each cell oval in shape, where the pressure 

 of the surrounding mass allowed it characteristic development, 

 but frequently compressed, so as merely to show its rounded 

 extremity. In the most perfect form the cell appeared 

 suddenly flattened towards one extremity, and at the other 

 frequently marked by an oval depression (sketched, magnified, 

 see fig. 2, 3) extending about half across it, surrounding a 

 slightly raised convex spot, — a peculiar marking I have not 

 noticed in other galls. The exterior of the cells, where 

 exposed, is shaggy, and sometimes marked by irregular 

 striae; and the aggregate mass much resembles in its 

 irregularly lobed form a miniature raspberry. 



In the case of the Lucombe oak the galls were rather 

 smaller, so as to be entirely included in the acorn-cup, which 

 is abnormally contracted into a globular form, closed at the 

 top ; the gall also is composed of rather fewer cells, and 

 these are occasionally separable, and somewhat more 

 symmetrically arranged, and occasionally with the peculiar 

 depressed mark. In other rcspecls, both of form and colour, 

 shagginess of exposed surface, and crLsp woody walls to the 

 single-chambered cells, the galls exactly correspond, and 

 appear to me the work of one gall -maker. The very great 

 number of gall-diseased acorns on this tree was also observable, 



