221 
The species of the Gall-Midges already known, now 
exceeding 300 in number, are distinguished from each other by 
the differing venation of their wings, the number, shapes and 
clothing of the joints of the antenne, and the greater or less 
hyalescence of the wings. I propose in a subsequent paper to 
give a synopsis of the genera, with figures of the important 
characters above alluded to. ‘ 
It is in the preparation made by the parent fly for its 
offspring, and the behaviour of the larva during the weeks or 
months of its active life, that is centred the interest so many 
naturalists have felt for these Gall-Midges. 
With a few notable exceptions the larva lives within the 
tissues, or upon some modified parts of plants, disfiguring them, 
and causing by its presence abnormal growths or abortions, 
such abnormalities going by the general name of Gattis. In 
this habit they resemble certain other orders of INSECTA and 
some ARACHNIDA, and their galls are in many cases not to be 
distinguished in external appearance from those of the Cynipi- 
dae (true gall-flies), Tenthredinidae, (the saw-flies,) the Phytopi 
(Mites), or the Coleoptera (Beetles). Certain species of other 
families of Diptera possess a similar habit, but among Diptera, 
the Cecidomyide are the Gall Makers. It may be of local interest 
to mention that the well-known red hairy gall on the Wild Rose, 
made by a Cynips, is called on the Cotteswolds, “Robin Red- 
breast’s pincushion.” 
Under the general term of Gall (confining ourselves strictly 
to those of the Cecidomyide), are included many varied plant 
malformations differing in character and degree of modification 
of the plants’ organs and tissues; and many attempts have been 
made to arrange and classify these structures according to their 
forms and external appearances, and the parts of the plant they 
have modified. 
To allude to but a few of these modifications; Galls take 
the form of scales on leaves, in appearance like mere spots, and 
but a fraction of a millimetre in thickness; some such have 
actually been taken for micro-fungi and so described. Wart- 
like lumps, minute spheres, cylinders and cones, as on both sides 
Q 2 
