CHAP. CV. 



C'ORYLA^CEvl!;. (^UE'RCUS. 



182; 



16.50 



destined to wither and drop oft' as soon as their office of shedding the pollen 

 is terminated ; hut if, before they have done so, they are seized and appro- 

 priated by the fly, they become permanent, and remain so until the maggot 

 within the gall ceases to feed. From this circumstance, it is evident that the 

 flow of the sap is in the proportion to its consumption ; that ' bursting buds, 

 lengthening shoots, expanding leaves, swelling fruit,' or swelling galls, equally 

 attract currents of sap, and, in the last instance, even into a foreign channel ; 

 proving what Du Petit Thouars, and other botanists, have long ago advanced 

 as their opinion; viz. that the growth of a tree is not caused by the motion 

 of the sap, but the movement of the latter 

 is caused by the distension of the various 

 members." (/. Main in Gard. JMag., vol. 

 xii. p. 708.) The artichoke gall, or oak 

 strobile (^g. 1650.), is probably the "oak 

 nut " of the ancients : it is about the size of 

 a filbert, and, from its closely imbricated 

 scales somewhat resembling a fir strobile or 

 an artichoke, it has so been termed. {Reauni. 

 Mem., torn. iii. pi. 43. f. 1 — 12.) It is 

 produced by the Cynips qudrcus gemmae, 

 and is a most beautiful foliose gall ; for the 

 developement of the bud, although per- 

 verted, not being wholly prevented, the 

 leaves are gradually evolved. " These galls," 

 says Professor Burnet, " throw much light 

 upon the natural metamorphoses of plants, 

 especially on the transition from leaves to flowers, by the abortion of 

 the axis of the bud, and the leaves hence becoming whorled ; and, when 

 the axis of each leaf (that is, its petiole and midrib) becomes in like manner 

 curtailed, the gall assumes a still more florid form. Occasionally, in the 

 oak, but more frequently in the willow, the gallic acid changes the ordinary 

 green colour of the abortive leaves into a bright red, giving the preter- 

 natural growth very much the appearance of a rose ; and hence 5alix i/elix, 

 in which this occurs, has been not inaptly called the * Rose Willow.' The 

 hedegiiar, or hairy gall (Galla capillaris of the ancients), is a peculiar and 

 very beautiful species, though rather scarce, for which reason it was formerly 

 much esteemed. In structure it is very similar to the bedeguar of the rose ; 

 and it is usually situated in the axils of the leaves. It is considered excellent 

 as a styptic. Whether the ' oak wool,' flocks of which were once so famed 

 as wicks for lamps, but which, as Parkinson shrewdly observes, will not burn 

 * without oyle or other unctuous matter, as Pliny saith it will,' was the same 

 as our cottony or woolly gall, the description of the ancient Galla lanata 

 renders doubtful ; for the flocks of wool are said to have been enveloped in a 

 hard case; which structure is rather more analogous to that of our clustered 

 galls, usually about six or seven in a group, and each the habitation of a 

 separate grub ; as in them the little hard galls containing the insects are 

 included in a soft and spongy, though not woolly, material, and are defended 

 externally by a hard ligneous case: these may by some, however, be es- 

 teemed the oak nuts, rather than the strobile one before alluded to." (Amcen. 

 Quer. in Eidoden.^ 



The oak berries, described as " sticking close to the body of the tree," 

 were, doubtless, the galls produced by the Cynips quercus ramuli, or C. q. 

 corticis ; and the UVae quercinae, or oak grapes, were, not improbably, the 

 aggregation of similar galls, which are occasionally found upon the roots, or 

 at the line of demarcation between root and stem, and which are produced by 

 the Cynips quercus radicis. We have been favoured by the Rev. W. T. 

 Bree with a very fine specimen of this gall, which he discovered, on the 22d 

 of February, 1837, on the root of an oak tree (just at the surface), and which 

 was at that time inhabited by a number of the Cynips quercus radicis in the 



6 c 



