ON MICROSCOPIC DISCOVERY. 



617 



opaque. The wings of moths and butterflies 

 tire mostly farinaceous, covered with a fine dust; 

 by the assistance of the microscope, we dis- 

 cover that this dust is a regular assemblage of 

 organized scales. Under the wings of most 

 insects which have only two, there is a small 

 head placed on a stalk, frequently under a 

 little arched scale ; these are called halttres, 

 or poisers ; they appear to be rudiments of 

 their hinder wings," or substitutes for them : 

 " it has been supposed that they serve to keep 

 the body in equilibrio when the insect is fly- 

 ing. The elytra, or exterior wing cases, are 

 harder and more opaque than the wings under 

 them ; they are generally highly polished, and 

 often enriched with various colours, adorned 

 with ornamental flutings, and studded with 

 brilliants, whose beauties are beyond descrip- 

 tion. All these ornaments are united in the 

 wing case of the curculio imperiulis, or diamond 

 beetle, one of the richest and most magnificent 

 creatures in nature. It is said, that in the 

 Brazils, whence they come, it is almost im- 

 possible to look at them on a sunny day, when 

 ihey are flying in little swarms, so great is 

 the glowing splendour of their heightened 

 colours." 



Our illustrations of wings will be found 

 in plate 34, figs. 22, 23, and 25. To have 

 given with full effect the remarkable details 

 in these members, they must necessarily have 

 been drawn upon a large scale, and by con- 

 sequence have limited the variety of our 

 objects. The reader must, therefore, consider 

 these figures as little more than an indication 

 of the wondrous beauty and delicacy observ- 

 able in these objects when subjected to deep 

 magnifying powers. 



Fig. 22. The wing of a gnat. This object 

 is remarkable for the delicate punctce, or dots, 

 that cover the entire membrane, and from each 

 of which an exceedingly fine spine, or point, 

 juts out. The fibres of the wing are serrated, 

 or, more properly, armed with thorny projec- 

 tions, similar in character to fig. 9. The 

 outer margin is thickly set with a vast num- 

 ber of small scales, or feathers, much resem- 

 bling those on the wings of butterflies. The 

 low power under which we have exhibited 

 this object is not sufficient to develope the 

 true character of the minute details. 



Fig. 23. The wing of an ichneumon fly . This 

 object is shown under the same power as the 

 preceding ; and it will be seen that the dots on 

 the membrane, and the spine of each dot, are 

 much less delicate in this wing than in that 

 of the gnat. The upper margin is serrated. 



Fig. 25. The wing of an earwig. " Though 

 the earwig is so common an insect, yet few 

 people know that it has wings, and fewer yet 

 hive seen them ; they are of a curious and 

 elegant texture, and wonderful structure. The 



VOL. II. 



upper part is crustaceous and opaque, while 

 the other part is beautifully transparent. They 

 fold up into a very small compass, and lie 

 neatly concealed under the elytra, which are 

 not more than a sixth part of the wing in size. 

 The insect shuts up the ribs like a fan ; the 

 strong muscles used for this purpose are seen 

 at the upper part of the figure. The ribs are 

 extended from the centre to the outer edge, 

 others are extended only from the edge about 

 halfway ; but they are all united by a band 

 at a small but equal distance from the edge ; 

 the whole evidently contrived to strengthen 

 the wing, and facilitate the various motions 

 thereof ; so that in these wings you find all 

 the motions that are in the most elaborate and 

 portable umbrellas, executed with a neatness 

 and elegance surpassing description." 



" The wings of butterflies are covered with 

 a fine dust which renders them opaque, and 

 produces those beautiful and variegated colours 

 by which they are so richly adorned, and so 

 profusely decked. If this be wiped oft, you 

 find the remaining part, or naked wing, to 

 consist of a number of ribs, like those in the 

 leaves of plants, but of a crustaceous or talcy 

 nature ; the largest rib runs along and fortilies 

 the exterior edge of the wing ; the interior 

 edge is strengthened by a smaller vessel or 

 rib. The ribs are all hollow, by which means 

 the wing, though comparatively large, is very 

 light. The substance between the ribs, which 

 constitutes the body of the wing, resembles 

 talc, and is surprisingly thin and transparent; 

 as this is extremely tender, one use of the 

 scales may be to protect it from injuries. 

 When the fly emerges from the chrysalis, the 

 wings are soft and thick, and if they be ex- 

 amined in that state, will be found to consist 

 of two membranes that may be raised up and 

 separated, by blowing between them with a 

 small tube : the ribs lie between these mem- 

 branes. Ever since the microscope WHS in- 

 vented, the dust that covers these wings has 

 engaged the attention of microscopic observers; 

 as by this instrument it is found to be a regular 

 collection of organized scales of various shapes, 

 in whose construction there is as much 

 symmetry, as there is beauty in their colours. 

 Their shapes are not only very diiierent in 

 butterflies and moths of various species, but 

 those on the same moth or fly are also found 

 to diifer. Of the scales, some are so long and 

 slender that they resemble hairs, except that 

 they are a little flattened and divided at the 

 ends, some are short and broad ; some are 

 notched at the edges, others smooth ; some are 

 nearly oval, while others are triangular : they 

 are mostly furnished with a short stalk or stem 

 to fix them to the wing." The prodigious 

 number of small scales which cover the wings 

 of papillae, and their regular arrangement, 

 4 i 



