[ 14,1 ] 



X. Further Hemarka on the Organs found on the bases of the Halteres and Wi/ngs of 

 Insects. By J. B. Hicks, Esq., M.I). Lond., F.L.S. 



Read June 2n(l, 1857. 



In a former paper, published in the Journal of the Linnean Society*, I endeavoured to 

 describe a curious and beautiful structui-e 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 Dijjtera and other insects, and stated that generally the organs in question 

 on the posterior wiags 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 structiu*es 

 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 thrak the organ was 

 one of special sensation, and that, sitviated 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 di-awing (Tab. XXVII. fig. 1) 

 made from a specimen which I have preserved, shoTiving most distinctly the nerve in its 

 whole course, giving off in its passage by the groups of vesicles, numerous branches which 

 can be traced into their bases. This may be seen by any one taking due care in the 

 preparation of the specimen. The dramng is from the second wing of a Longicom beetle 

 {Strangalia elongata) ; though perhaps every ^ving will not show it well, on account of 

 the position of the nervm'es. I may here mention the method employed, Avliich is one, 

 I believe, frequently in use : — After cutting off the Aving and washing it well in water or 

 spirits of wine, and di-aining 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 clilorine : a little chlorate of potash, and a few drops of hydrochloric acid, 



• Vol. i. p. 13(5, Nov. 1, 1856. 



