THE OAK. 273 
most powerful of all astringents. Galls are produced on 
various species of the oak by insects of the genus Cynipide. 
The galls of commerce grow on the Quercus infectoria, an 
oak indigenous to Asia Minor, Syria, and Persia; a shrubby 
plant which sheds its leaves, and seldom exceeds the height of 
six feet. The gall-flies puncture the tender leaves or shoots 
and deposit their eggs, around which the gall accumulates. 
The most remarkable galls are those formed on the male 
blossom of the British oak. These catkins appear in May, 
from one to two inches long, and having shed their pollen, 
become deciduous and drop from the tree in June ; but if they 
have been seized on by the insects and punctured while in a 
growing state, they remain attached to the tree until the galls 
are perfected, presenting the appearance of the fruit-stalks 
and berries of a bunch of unripe currants. 
Q. Cerris (Linneus) : The Mossy-Cupped or Turkey Oak.— 
This tree is a native of the middle and south of Europe, and 
the west of Asia. It was introduced into Britain in 1735. 
It is a tree of an elegant appearance, as hardy as the common 
oak, of much faster growth, and it grows vigorously even in 
very poor soil. It ripens its acorns like the British oak, and 
the mode of propagation detailed for that tree is alike suit- 
able for this species, with this difference, that, as Turkey oak 
seedlings are generally taller than the other, it is better to 
transplant them at the age of one year than.to allow them to 
remain two years in the seed-beds. This species is remarkable 
for producing a great number of varieties from seed, which 
differ greatly in the size and shape of their leaves. It appears 
particularly apt to hybridize with the evergreen oak; and 
frequently in seed-beds of young plants a considerable number 
of sub-evergreen plants may be selected. The leaves of the 
tree are of a glossy green above, inclining to white underneath. 
They are lobed and sinuated or dentated irregularly. They 
die in autumn ; but, like those of the young beech, they often 
adhere to the tree throughout the winter. In good soil the 
tree attains the height of forty feet in twenty or twenty-five 
years, and a proportionable girth, The tree generally ad- 
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