596 CUPULIFERiE. 



to Cambay by way of Mekka, and that they are worth a great deal in 

 China and Java. From the statements of Porter Smith ^ we learn that 

 they are still prized by the Chinese, 



Formation — Many plants are punctured by insects for the sake of 

 depositing their eggs, which operation gives rise to those excrescences 

 which bear the general name of gall.^ 



Oaks are specially liable to be visited for this purpose by insects of 

 the order Hymenoptera and the genus Cynips, one species of which, 

 Cynips Galloi tinctorice Olivier {Diplolepis Gallce tln-ciorice Latreille), 

 occasions the galls under notice. 



The female of this little creature is furnished with a delicate borer or 

 ovipositor, which she is able to protrude from the extremity of the 

 abdomen; by means of it she pierces the tender shoot of the oak, and 

 deposits therein one or more eggs. This minute operation occasions an 

 abnormal affluence to the spot of the juices of the plant, the result of 

 which is the growth of an excrescence often of great magnitude, in the 

 centre of which (but not as it appears until the gall has become full- 

 grown) the larva is hatched and undergoes its transformations. 



When the larva has assumed its final development and become a 

 winged insect, which requires a period of five to six months, the latter 

 bores itself a cylindrical passage from the centre of the gall to its 

 surface, and escapes. 



In the best kind of gall found in commerce, this stage has not yet 

 arrived, the gall having been gathered while the insect is still in the 

 larval state. Iti splitting a number of galls, it is not difficult to find 

 specimens in all stages, from those containing the scarcely distinguishable 

 remains of the minute larva, to those which show the perfect insect to 

 have perished when in the very act of escaping from its prison. 



Description — Aleppo galls ^ are spherical, and have a diameter 

 of ^jj to Y^^ of an inch. They have a smooth and rather shining surface, 

 marked in the upper half of the gall by small pointed knobs and ridges, 

 arranged very irregularly and wide apart ; the lower half is more 

 frequently smooth. The aperture by which the insect escapes is always 

 near the middle. When not perforated, the galls are of a dark oHve 

 green, and comparatively heavy ; but after the fly has bored its way out, 

 they become of a yellowish brown hue, and lighter in weight. Hence 

 the distinction in commerce of Bhie or Green Galls, and White Galls. 



Aleppo galls are hard and brittle, splitting under the hammer; tliey 

 have an acidulous, very astringent taste followed by a slight sweetness, 

 but have no marked odour. Their fractured surface is sometimes close- 

 grained, with a waxy or resinous lustre ; sometimes (especially towards 

 the kernel-like centre) loosely granular, or sometimes again it exhibits a 

 crystalline-looking radiated structure or is full of clefts. The colour of 

 the interior varies from pale brown to a deep greenish yellow. The 



^ Mat. Med. and Nat. Hist, of China, gall, for descriptions of some of which, see 



1871. 100. Guibourt, UK des Drogues, ii. (1869) 292; 



2 French writers, as Moquin-Tandon, dis- and for information on the various gall- 



tinguish the thick- walled galls of Cynips insects of the family C'?/Hips Wee and the ex- 



from the thin, capsular galls formed by crescences they produce, consult a paper 



Aphis, terming the former oalles and the by Abl in Wittstein's Vierteljahresschrift 



hAter coques (shells). fi'ir prah. Pharm. vi. (1857) 343-361. 



^ There are many other varieties of oak 



