6 POPULAR SCIENCE REVIEW. 
varying from a quarter to one inch in length, may with pro- 
priety be deemed a variety intermediate between “ Sessiliflora” 
and “ Pedunculata,” and a comparison of the three will sub- 
stantiate its claim to this title. 
As a tree it is impossible to make out any specific character 
from its mode of growth, and, indeed, without the fruit, it is 
extremely difficult even to distinguish it as a variety. 
It occurs — only occasionally — in the Cotteswold district, and 
we suppose the same elsewhere. One meets with it here and 
there in the hedgerows, and in Oakley Park, the seat of Earl 
Bathurst, we can point out a few specimens. 
Passing from the subject of the varieties of our British oak, 
it now remains to mention a most formidable enemy by which 
it has of late years been attacked, and so exclusively, that in 
plantations where may be found the American oaks, the Ilex oak, 
and Turkey oak trees, it has been the only one subjected to the 
operations of the new gall pest. It has long been known that our 
native oaks were subject to excrescences of different forms and 
sizes, such, for example, as oak apples, oakleaf galls, oak span- 
gles, &c., all of which were 
ascertained to be caused by 
several species of cynips ; but 
lately, we have to lament 
the introduction of a new spe- 
cies of the same insect, form- 
ing a new kind of gall, which, 
instead of attacking the backs 
of the leaves, as does the 
oakleaf gall, occupies the 
stem that belongs to the leaf ; 
in fact, the attacked leaves 
seem to be converted into 
bunches of galls, as repre- 
sented in the adjoining figure, 
which presents an illustration 
of the new pest. They are 
hard galls, more or less like 
the “ nut-gall ” from Aleppo, 
of which ink is made, and it 
will be seen that the little 
twig supports no less than 
five galls, in the interior of 
each of which may be found 
the maggot or larva of an 
insect ; and, as this is effected at the expense of the buds and 
leaves, the mode of injury must be obvious, as the new twigs 
which would have been formed, had there been no galls, would 
