]38 BETTISH OAK GALLS. 



Parasites, Nos. 19, 20, 22, 32, 83, 36, 39, 44, 55, 56, 58, 63, 65, 

 80, 81, 82, 84, 85, 86, 90, 91, 92, 93, 97, 98, 99, 100, 101, 102, 106, 

 107, 116, 118, 148, 151, 153, 154, 155, 156, 157, 160, 164, 167, 168, 

 169, 170, 171, 172, 173, 174, 176, 180, 184 (see pp. 150-152). 

 Inquilines, Nos. 71, 73. 



Alternate agamic generation : Biorhiza aptera, Fabr. 



Hyper-parasites and other insects and creatures 

 that have been found upon, within, and reared from 

 galls of T. terminalis are very numerous. The student 

 desirous of following the subject will find them 

 enumerated in ' The Entomologist,' No. 152, February, 

 1876, pp. 29-42; also in 'Brit. Phyto. Hymen.,' 

 vol. iv, p. 120, and in ' Alternating Grenerations,' 

 pp. 77-79. 



This gall received its specific name because of its 

 propensity in developing, usually, from a terminal 

 bud. It, however, develops from axillary buds with 

 equal frequency and vigour. 



It is an exceedingly familiar object to persons living 

 in rural districts, and also to those who notice oak 

 trees while passing along country roads, or through 

 woods during the months of May and June, and also 

 July, if the season is late. 



The autumn-winter condition of the gall is not so 

 well known. When partly decayed, and most of the 

 inhabitants have escaped from the tissues, the remnant 

 is so unlike its summer condition that few persons 

 regard it as connected with the soft and delicately 

 tinted oak-apple of May and June. 



When Jjiorkiza apfera deposits her numerous ova 

 she almost severs the bud from the twig with the 

 continuous puncturings of her ovipositor. Immedi- 

 ately, therefore, gall growth begins, the few remaining 

 connecting cells are ruptured, and the whole of the 

 bud (with, perhaps, the exception of a few basal 

 outer leaf scales), is lifted from its base, and remains 

 adherent to the surface of the gall. The bud may 

 thus be retained in an upright position, or in a jaunty 

 attitude, and unless removed by wind, or other causes, 



