CHAP. XI.] CUPULIFER^. 195 



(Q. PheJlos) ; and the Turkey, Fulham, and Lu- 

 combe Oaks (Q. Cerris and its varieties). All Oak 

 trees are very liable to be attacked by a species 

 of gnat, and which produces excrescences on the 

 branches. The oak apples of the British Oak, 

 and the galls of Qiiercus infectoria. which are 

 used in making ink, are of this nature. The 

 Kermes, an excrescence found on Quercus cocci- 

 fera^ is the work of a kind of Coccus, similar 

 to that which produces the cochineal on the 

 Opuntia. 



The timber of all the European Oaks is 

 remarkably durable ; but that of nearly all the 

 American Oaks, except Quercus virens^ is coarse 

 grained, and so porous that it cannot be used 

 for wine casks. The cork trees are generally 

 grown in Spain ; and as the cork when taken 

 off the tree, curves round, it is laid upon the 

 ground and kept flat w'ith heavy stones ; while 

 a fire is made upon it with the branches, so as 

 to heat it through, after which it remains flat 

 when the stones are removed. 



THE GENUS FAGUS. 



The Beech {Fagus sylvatica) bears very little 

 resemblance to the Oak. The male flowers are 

 in globular catkins (see a in Jig. 87), each 

 flower consisting of a bell-shaped calyx (5), cleft 

 into five or six teeth, and containing eight or 

 o 2 



