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 X. Further Remarks on the Organs Jound on the bases of the Halteres and Wi ings of 
Insects. By J. B. HICKS, Esq., UD. Lond., F.L.S. 
Read June 2nd, 1857. 
IN à former paper, published in the Journal of the Linnean Society *, I endeavoured to 
describe a curious and beautiful structure to be observed at the base of the halteres of 
‚the Diptera, and a similar but less elaborate condition on the subcostal nervures of the 
wings of both Diptera and other insects, and stated that generally the organs in question 
on the posterior wings of the 4-winged tribes were the more numerous: I also proceeded 
` to show, that into the halteres, as also into each of the wings of insects in general, could 
be traced a nerve of considerable size, varying in the different tribes and genera in that 
particular, and that the nerve proceeding to the posterior wings was generally the larger, 
and also that the one supplying the halteres of the Blow- and Drone-fly was the largest 
nerve in. the insect, except the optic. I may here repeat, that each of these structures 
consists of very thin and transparent, hemispherical, or more nearly spherical projections 
from the cuticular surface, beneath which the wall of the nervure is deficient, so as to 
allow a free communication with its interior ; these organs are arranged in rows on the 
halteres, and in variously shaped groups in the wings. I concluded that the nerve pro- 
ceeded to these structures, inasmuch as there was no muscle in the wing or halteres, and 
that consequently the nerve must be one of sensation ; and looking at the elaborate and 
regular disposition of the structures composing it, I was induced to think the organ was 
one of special sensation, and that, situated as it was near the great thoracic spiracle, as 
well as exposed to constant and rapid currents of air, it seemed not improbable that it 
was connected with the olfactory sense. 
At that time I had not been able to prove the actual connexion between the nerve and 
these vesicles, but I have now the pleasure of exhibiting a drawing (Tab. XXVII. fig. 1) 
— made from a specimen which I have preserved, showing most distinctly the nerve in its 
whole course, giving off in its passage by the groups of vesicles, numerous branches which 
can bé traced into their bases. This may be seen by any one taking due care in the 
preparation of the specimen. The drawing is from the second wing of a Longicorn beetle 
(Strangalia elongata); though perhaps every wing will not show it well, on account of 
the position of the nervures. I may here mention the method employed, which is one, 
I believe, frequently in use :—After cutting off the wing and washing it well in water or 
spirits of wine, and draining off the major part by blotting-paper, I immerse it in spirits 
of turpentine for a week or two, after which it is placed in Canada balsam between glass 
in the usual way, taking care not to heat it, as that renders the nerve too transparent. 
. In those parts which are too dark for observation, I have been enabled to render them 
colourless by chlorine: a little chlorate of potash, and a few drops of hydrochloric acid, 
. * Vol. i. p. 136, Nov. 1, 1856. 
