88 



BL'ITLSH OAK GALLS. 



This gall stands more or less ol)liquelj from the 

 twig, upon a hemispherical base formed of the aborted 

 l)ud out of which it has grown. It maj be sessile, or 

 attached by a short peduncle. It is in the form of 

 a narrow cylinder, the distal end of which bears a 

 small, glabrous, glossy, mastoid process. 



Its growth occupies al^out three weeks, by which 

 time it reaches maturity and then falls to the ground. 



A special feature characterising the growth of this 

 gall is the hemispherical reddish-l)rown base which is 

 firmly adherent to the twio- in a leaf axil. 



The gall appears to l^e rare. I have never found 

 more than the one specimen ilhistrated, although 



Fig. 9. — Galls caused by Aphilothrix 3Ialpig]iii. a. Aftei' Cameron. 

 B, c. After Adler, each x 2. d. The same specimen as in Plate 

 XXIII, div. A. X 4. dele, ad nat. E.C. 



f|uantities of galls of Amlricva miduH are found year 

 after year in the same wood. I found it in a wood at 

 Hastings during September 1901, and knowing for 

 certain that I should not be able to visit the spot again 

 for several weeks, gathered it, but unfortunately failed 

 to rear the inhabitant. 



Cameron describes the gall as smooth. My speci- 

 men is clothed with numerous short, recurved, 

 adpressed hairlets, of a somewhat golden colour, 

 except at the apex, and devoid of ridges. Adler does 

 not refer to the presence or absence of hairlets. 

 (>ameron's illustration (' Brit. Phyto. Hymen.,' vol. iv, 

 Plate VII, fig. 2) corresponds as regards position, base, 

 size, and partly in outline, with my specimen. 



Adler, in 'Alternating Generations,' Fig. 12, illus- 

 trates two galls on a twig. They are sessile, and 



