WINGS OF INSECTS. 679 



"Wings of the Orihoptera (Grasshoppers, Crickets, &c), although 

 not by any means so solidified as those of Coleoptera, contain a 

 good deal of Horny matter ; they are usually rendered sufficiently 

 transparent, however, by Canada Balsam, to be viewed with trans- 

 mitted light ; and many of them are so coloured as to be very 

 showy objects (as are also the posterior fan-like wings) for the 

 Solar or (xas- microscope, although their large size, and the absence 

 of any minute structure, prevent them from affording much inte- 

 rest to the ordinary Microscopist. — We must not omit to mention, 

 however, the curious Sound-producing apparatus which is possessed 

 by most Insects of this order, and especially by the common House- 

 Cricket. This consists of the ' Tympanum ' or Drum, which is a 

 space on each of the upper wings, scarcely crossed by veins, but 

 bounded externally by a large dark vein provided with three or 

 four longitudinal ridges; and of the ' File' or 'Bow,' which is a 

 transverse horny ridge in front of the Tympanum, furnished with 

 numerous teeth : and it is believed that the sound is produced by 

 the rubbing of the two Bows across each other, while its intensity 

 is increased by the sound-board action of the Tympanum. — The 

 Wings of the Fulgoridoz (Lantern-flies) have much the same 

 texture with those of the Orthoptera, and possess about the same 

 value as Microscopic objects ; differing considerably from the 

 purely-membranous wings of the Cicadae and Aphides, which are 

 associated with them in the order Homoptera. In the order 

 Hemiptera, to which belong various kinds of Land and Water 

 Insects that have a Suctorial mouth resembling that of the com- 

 mon Bug, the wings of the anterior pair are usually of parchmenty 

 consistence, though membranous near their tips, and are often so 

 richly coloured as to become very beautiful objects, when mounted 

 in Balsam and viewed by transmitted light ; this is the case 

 especially with the Terrestrial Vegetable -feeding kinds, such as the 

 Pentatoma and its allies, some of the tropical forms of which 

 rival the most brilliant of the Beetles. The British species are by 

 no means so interesting ; and the Aquatic kinds, which, next to 

 the Bed-bugs, are the most common, always have a dull brown 

 or almost black hue ; even among these last, however, — of which 

 the Notonecta (Water- Boatman) and the Nepa (Water-Scorpion) 

 are well-known examples, — the wings are beautifully variegated by 

 differences in the depth of that hue. The Halteres of the Diptera, 

 which are the representatives of the Posterior Wings, have lately 

 been shown by Dr. J. B. Hicks to present a very curious structure, 

 which is found also in the Elytra of Coleoptera and in many other 

 situations ; consisting in a multitude of Vesicular projections of 

 the superficial membrane, to each of which there proceeds a 

 Nervous filament, that comes to it through an aperture in the 

 Tegumentary wall on which it is seated. Various considerations 

 are stated by Dr. Hicks, which lead him to the belief that this 

 apparatus, when developed in the neighbourhood of the Spiracles 

 or breathing-pores, essentially ministers to the sense of Smell, 



