ANDErCUS INFLATOE. 68 



small trees, but more generally on the lower than the 

 upper branches ; very rarely on scrub-oaks of less than 

 three years' growth. 



Andricus inflator, Hai-tig. 

 (Plate XI.) 



Andricus inflator, Adler, Miiller, Mayr, Moslev, Fitch, Cameron ; 

 Cynips inflator. Thorns. 



Eng^lish name of gall. — "The Twig Grail." 



Position of gall. — At the extremity of twig or shoot. 



Manner of growth. — Single, glabrous, sessile, glossy. 



Colours. — Grreeu, dark green, brown, dark brown. 



Average dimensions of a mature specimen. — Height, 

 15 mm. : l)readth, 10 mm. ; girth, 30 mm. 



May be sought during any month of the year. 



Growth is complete by the end of September. 



The typical condition of the gall is bilocular, but unilarval. 



The larva pupates in the gall. The imago emerges during 

 June to August. 



Parasites, Nos. 21, 56, 83, 87, 154. Inquiline, No. 110. 



Alternate agamic generation: Aphilothrix glolmli, Hai-tig. 



The gall results from the gall-wasp laying its egg in 

 the axis of the terminal l^ud. AYhen the bud develops 

 in the spring the apical portion remains whitish for a 

 long while. 



In all stages of development the gall is easily 

 recognisable. 



In some districts this gall is exceedingly abundant, 

 and many oak bushes have a very great number of the 

 galls on the twigs ; but there is not always a pro- 

 portionate abundance of the alternate generation in 

 the succeeding autumn. 



The egg is laid in the axis of a bud during September 

 or October by Aphilnfhri.v f/JohuJi. No gall-growth 

 takes place until the following spring, Avlien the larva 

 hatches. Rapid swelling of the tissues then l^egins, 

 resulting in an enormously thickened and stunted 

 shoot. During the summer leaves and occasionally 

 short twigs grow from the exterior of the gall. In 



