JUGLANDACES.  & 
their formation as given by Pereira. “ The Hymenopterous insects of the tribe called Gadicole, or Diploleparie ( Cu- 
vier, Regne Animal), are furnished with a terebara or borer, by means of which they are enabled to perforate the folia- 
ceous of cortical parts of plants for the purpose of depositing their eggs, along with an acrid liquor in the wound thus 
made. The irritation thereby produced, gives rise to influx of the juices of the plant to the wounded part, and an excre- 
scence is formed, which is termed a gall, (galla.) Here the insect undergoes its transformations; the egg produces the 
larva (or maggot), which feeds on the juices of the plant, and is changed into the pupa. This afterwards becomes the 
rfect insect (immago), and perforating the gall, escapes from its prison house. The external form and appearance of 
these productions are very constant, when formed by the same insect, on the same part of the plant; but the galls of 
different species of vegetables, as well as those of the same species, produced by a different insect, vary considerably. 
There is reason for believing that the form and appearance of the gall are determined more by the insect than by the 
plant; for we have sometimes on the same oak two kinds of galls, of very dissimilar appearance, produced by different 
insects.” ‘The insect producing galls is the Cynips Galle Tinctoria. (Ohver.) 
Galls are derived from several sources. Aleppo furnishes the best. Smyrna galls are more mixed. East India 
galls are brought from Bombay, and are said to be the product of Persia. They are of two kinds, Black or Blue Galls, 
and White Galls. : 
The former are of the size of a pea to that of a hazelnut, of a bluish-black tinge, tuberculated, with smooth inter- 
stitial spaces, without perforation, but a central cavity. They are hard, with difficulty reduced to powder, unorganized, 
but of crystalline structure, and destitute of odour, and possessed of a strong styptic taste. They have been plucked in 
the early stage of the insect. 
The white galls are larger, lighter, of a dirty white or yellow colour, having a perforation on the side, and are 
plucked after the insect has escaped. 
Galls contain tannin and gallic acid. An acid called ellagic has been announced by Braconnot, probably a pro- 
duct, and not an educt. Sir H. Davy found in them, tannin 26.00, gallic acid 6.2, mucilage 2.4, carbonate of lime 
2.4, lignin 63.00=100. The tannic acid affords bluish-black precipitates with the salts of iron. 
This article of the Materia Medica, in consequence of the large quantity of tannin, is powerfully astringent. In 
the arts, itis used for tanning and for dyeing. In medicine, galls are used in powder, in infusion, tincture, &e. 
Puate LXXXV.—Represents the plant with the galls attached, the fruit and inflorescence, and the insect. 
JUGLANDACES. 
LINDLEY. 
WALNUT TRIBE. 
JucLanpex.—De Candolle. | 
Essenriar Cuar.—Flomvers declinous. Sterile flowers in an ament. Perianth scaly, oblique, irregularly lobed. 
Stamens inserted on the receptacle, indefinite (three to thirty-six). Filaments short, distinct. Anthers thick, two- 
celled, bursting longitudinally. Fertile flowers with a single or double perianth, the outer four-parted, the inner 
(when present) of four pieces. Ovary inferior, one-celled. Ovule solitary, erect. Styles one to two, very short or 
sae Stigmas large, either two and lacerated, or discoid, and four-lobed. Fruit drupaceous, one-celled, with four 
( Bek <i partitions. Seed four-lobed. Albumen none. Cotyledons fleshy, two-lobed, wrinkled. Radicle superior. 
ag The plants belonging to this family are large sized trees, with alternate unequally pinnate leaves. A purgative 
= in the followin @ species; perhaps a similar one may be found in others. ¢ 
. II 
: Il 
