BRITISH GALLS. 107 
which the insects have escaped, showing that they had 
attained their full size. On the juices of the gall the 
enclosed insect lives, until it reaches its full term of 
imprisonment, when it eats its way through the gall 
and emerges into the world. In some cases, it under- 
goes the whole of its change within the gall, but in 
others, it makes its way out while still in the larval 
state, burrows into the earth, and there changes into 
the pupal and perfect forms. 
To the unassisted eye, the insect which forms the leaf- 
gall presents no especial attraction, as it is simply, to all 
appearance, a little black fly. When placed under the 
microscope, however, it soon proves to be a really beau- 
tiful creature, though not possessing the brilliant and 
gem-like hues which distinguish’ many of its relatives. 
The body still retains its blackness, but has a soft tint 
on account of the white and shining hairs with which it 
is thickly studded. The eyes are large, stand boldly from 
the head, and the many lenses of which these organs are 
composed are so boldly defined, that even in so small 
an insect they can be distinguished with a very low 
power of the microscope. Indeed, the inch and a half 
object glass is quite powerful enough to define them, 
while the half-inch glass makes them look like the pits 
in a lady’s thimble. 
The chief beauty of the insect, however, lies in the 
wings, which are very large in proportion to the size 
of the owner, are traversed by a few, but strong 
nervures, and glow with a changeful radiant lustre, like 
mother-of-pearl illuminated with living light. In order 
to see these wings properly, the insect should be laid on 
some black substance, and the light concentrated upon 
them by the various means which a microscopist can 
always employ. 
