24 BKITISH OAK GALLS. 



'\22 Ne/uroferus rivmismatis 21 i\". fnmvpeinih = 146 



galls. 



On another leaf, 14*5 x 7'5 cm. : 



5 Neurotervs ostreus . 12 Dryophartta divisn. 

 37 „ numi^mdtis 123^^. fumipemni< = 177 



galls. 



It is very remarkable that the alnindance of the 

 spangle galls in particular upon a leaf does not affect 

 its normal size, shape, outline, or thickness. There is 

 therefore no detriment to the foliasfe on account of the 

 presence of hundreds of thousands of these galls on a 

 bush or tree, nor is the growth and development of 

 either hindered. 



The galls on catkins undoul)tedly prevent the growth 

 of thousands of acorns, but that is of small consequence 

 since thousands more are available for seedling oaks, or 

 for pig food and small rodents. The value of the tree 

 is in its timber and its bark. 



In connection with the numerical abundance of galls, 

 two correspondents have kindly communicated the 

 following : " It may be of interest to you to know that 

 several oaks {peduncnhifa) which I specially noted in 

 May as having an almormal numl^er of red-currant 

 galls upon the catkins, are at the pi'esent time (August) 

 quite free from galls of any kind, but some little 

 ' shrubby ' oaks in their immediate vicinity have their 

 leaves covered with N. leiiticniaris. In other places in 

 the same wood the Turkey oak and our common oak 

 are growing side by side, so close that the branches 

 intermingle ; the Turkey oak is ({uite free from galls, 

 the others have mmiisinatis and lenticidaris in large 

 numljers, chiefly on leaves at the apex of the branches " 

 (E. W. Swanton, Haslemere, Surrey, in lit., September 

 4th, 1904). 



This latter peculiarity has Ijeen noticed on several 

 occasions by the author. So also has the strange fact 

 that enormous numbers of galls of several species will 

 be found in one part of a wood and nowhere else in the 

 same wood. 



