CHAP. CV. CORYLA‘CEH. QUE’RCUS. 1827 
inch in diameter, smooth on the surface next to the leaf, but hirsute and red 
on the outside: they are nearly flat, the thickest portion being the centre, 
where the point of attachment to the leaf is placed on the inside. This stalk, 
or funicular attachment, as it may be called, is very short, so that the excres- 
cence nearly lies flat upon the leaf. (See fig. 1652.a.) The Rev. W. T. Bree 
(Gard. Mag., vol. xii. p. 496.) calls them oak spangles, considering them to be 
the work of an insect. They are mentioned by several authors; but Mr. West- 
wood cannot find that their history has been satisfactorily traced by any writer 
upon the economy of insects. Nees von Esenbeck observes of these oak 
spangles, “ Mirum tamen, gallas esse, quas etiamsi frequentissimas omnium, 
nemo hucusque incola sua fetas invenerit, vel guomodo oriantur cognoverit.” 
(Hymen. Monogr., ii. p. 266.) Réaumur has described and figured them 
(Mém., tom. iii. mém. 12. pl. 42. f. 8.10.) under the names of galles en 
champignon, from their resemblance to a flat mushroom. He was never, 
however, able to discover any appearance of an internal cavity ; but he adds, “ Il 
faut pourtant qu’il y en ait dans le milieu de quelques unes, car M. Malpighi 
assure l’avoir observé.” He, however, discovered that the space between the 
under side of the excrescence and the leaf was the residence of a small worm, 
of an oblong form and yellowish amber colour, with two small points on the 
front of the head. Under some of these galls one or two only were found, 
but as many as a dozen under others. Fabricius, without alluding to these 
worms, gives the excrescences as the galls of Cynips longipénnis, or Dipldlepis 
lenticulatus of Olivier, with the observation, “ Habitat in galla parva depressa, 
monothalama Galliz. Mus. Bosc. ;” and Coquebert has figured this species of 
cynips from the Boscian cabinet with two specimens of the galls, which are, 
however, represented so small, and so unsatisfactorily, that it is doubtful 
whether they be identical with Réaumur’s galles en champignon. But in 
the collection of Chalcidide formed by Dr. Nees von Esenbeck, above 
mentioned, are contained specimens of this excrescence, accompanied by a 
specimen of the Eurytoma signata; and in this author’s Monog. Hymen, Ichn, 
Affin., vol. ii.p. 43., is the remark : “ Observavi etiam, Septembre mense, hujus 
speciei feminam, cum gallam illam orbiculatam depressam lenticularem umbo- 
natam basi arcte appressam rubram hirsutam, que in pagina foliorum quercus 
inferiori frequens occurrit, ictu vulneraret. Non causa igitur hujus speciei, 
sed parasita incole ejus, videtur.” This inhabitant, on the authority of 
Geoffroy (who is, however, silent on the subject) and Fabricius, he doubt- 
ingly considers to be the Cynips longipénnis Fas. But the real habit of this 
Eurftoma, as he had previously ascertained, is to deposit its eggs in the gall 
produced by Cynips quércus gémmz above described. The puncturing of 
the gall by the parasitic Eurytoma is not a proof of there being any internal 
inhabitant; because, as we learn . 
from Réaumur, one or more 
worms take up their abode be- 
neath the excrescences ; and it 
might be these which the Eury- 
toma endeavoured to pierce 
with its ovipositor Mr. West- 
wood has, at the end of the 
month of September, disco- 
vered many of the minute larve 
mentioned by Réaumur, but 
never more than a single spe- ¢ 
cimen under each, In fig. 1652. 
6 shows the insect of the na- 
tural size; c,d,thegalls reversed, 
and rather magnified, with dif- 
ferent-sized larve; e, larva 
magnified. It was chiefly under the larger-sized and more hairy excrescences, 
the margins of which were deflexed, that he discovered these larve, which 
6c 3 
