116 BRITISH OAK GALLS. 



Parasites, Nos. 6, 7, 9, 19, 43, 44, 46, 56, 67, 77, 88, 96, 125, 

 151, 166, 180. Inquilines, Nos. 60, 110, 134, 142, 145. 



Alternate sexual generation-: Spathegastev Taschenhergi. 



This is the largest, most conspicuous, and brightest 

 coloured, of the leaf galls. Very few galls can vie 

 with it for beauty. 



It grows on the under-surface of the leaf, firmly 

 attached to the rib by an exceedingly small projection 

 of its own growth. The basal portion is not flattened 

 as is the case with most of the leaf galls, but there is 

 often a long narrow indentation caused by the rib of 

 the leaf. Specimens are occasionally to be seen on the 

 u]3per sm^face of the leaf; they are usually rather 

 smaller than the normal size. Some turn dark red 

 and reddish-brown when only half developed, and are 

 more succulent than others not so coloured. 



The composition of the gall, is a tough outer rind 

 enclosing a soft, loose, and spongy parenchyma, in the 

 centre of which is the larval cavity without any inner 

 gall. When old, and the moisture has dried, the 

 surface becomes greatly wrinkled. 



It is somewhat variable in size, but not excessively 

 so. The largest I have found measured 23 mm. in 

 diameter. Upon examination it proved to be perfectly 

 free from parasites and inquilines. 



The numbers on one leaf also fluctuate somewhat. 

 Three, four, and five are frequently seen ; six, seven, 

 and eight occasionally. The largest number I have 

 found on one leaf is twelve. Eighteen on two leaves 

 — although not English specimens — as shown on Plate 

 XLV, are worthy of recording, as also is the Frontis- 

 piece. 



Some galls fall from the leaves at the approach of 

 autumn, others continue to adhere, although the leaf 

 itself has fallen. 



The imagines are easy to rear ; some emerging 

 during October and November, others in the following 

 spring. 



