16 
These tiny semi-globular elevations cause the leaf to appear 
as though it had been sprinkled with some kind of tiny dark red 
seed. When once these leaves have been examined they can be 
recognised again without difficulty. The underside of the leaf 
presents a striking contrast to the upperside ; it is of a very pale 
green, almost bordering on a yellowish colour. With the aid of 
a tolerably powerful magnifying glass it will be seen that there are 
numbers of minute pits, the mouths of which are slightly swollen 
above the plane of the leaf. These depressions exactly 
correspond to the pimples on the other side. A few of the 
pimples develop on the underside, in which case the opening of 
the pit is on the upper side of the leaf. 
The leaves do not appear to be diminished in area from their 
normal size, because of the growth of these galls, nor are they 
contorted in shape ; indeed, their appearance is enhanced rather 
than otherwise. These swellings are produced by a gall mite. 
The mischief which these insects do is very considerable 
when compared with their minute size. They are seldom 
observed moving about during the day, and it is still a matter of 
speculation as to how they spread themselves so easily all over 
the buds of a tree and along a hedge row, seeing they are 
destitute of wings, and do not jump. Being semi-transparent in 
colour and of a very restless nature, it is most difficult to study 
them microscopically when alive, and when dead they become 
flaccid, whereby increasing the difficulty of a correct delineation. 
They are very minute ; several hundreds may he found inhabiting 
one ordinary size bud of a currant bush, and considerable 
numbers in each swollen gall on the leaves. 
Time has not allowed a review of such interesting topics as 
the life history and delineations of the insects which cause all 
these growths, the methods these insects employ in depositing the 
eggs, and the way in which the various structures are built up 
until they form the perfect gall; as also the phenomena of 
parthenogenesis, and the alternating generations of the species. 
On all these points they furnish unique illustrations. 
The object of this paper has been, firstly, by describing the 
shapes, appearances, and the usual positions scme of the most 
common and familiar kinds of vegetable galls occupy, to enable 
you, when collecting, easily to recognise them ; and. secondly, in 
so doing to create such an interest in them as will lead to 
thoughtful and patient study, a study which would be materially 
helped by collecting, preserving, and mounting as many examples 
as possible, and I trust that within the past hour the first has 
been attained, and during the coming year the second will 
result in the acquirement of a new pleasure to many who have 
been most kind and patient listeners this evening. 

