PARTS OF INSECTS, AND MISCELLANEOUS OBJECTS. 121 



dust, resplendent with the most brilliant colors, adorning their variegated surface. 

 When this dust is examined by the microscope, it is discovered to consist of a 

 vast number of minute feathers or scales, differing in form, and as remarkable 

 for the elegance and symmetry of their structure as for the beauty of their hues. 

 Their shape not only varies in different insects, but the same insect possesses 

 feathers of different forms. Some are long and slender, others short and broad ; 

 these are smooth at the edges, and those serrated or notched ; one kind is tri- 

 angular and a second oval. When viewed under the microscope, these scales are 

 found to be terminated by a short stem, that connects them with the wing, and 

 their surfaces are grooved in lines and stripes, which take different directions in 

 different scales. In some feathers two or more sets of lines are discerned cross- 

 ing each other. When this feathery dust is brushed away from the wing of a 

 butterfly, the surface below appears like the wing of the Hemerobius a network 

 of ribs connected by a delicate, transparent, and elastic membrane. The ribs are 

 hollow, by which contrivance, a wing, though broad and extended, still retains its 

 lightness, and on the membrane rows of dots are perceived, where the stems of 

 the scales were attached to its surface. On those parts where the dust remains, 

 the little particles are seen magnified into feathers, symmetrically arranged and 

 overlapping each other like the scales on a fish. These several appearances are 

 beheld in drawing 195, which represents a portion of the wing of a butterfly, 

 called the Papilio Archippus, partially divested of its scales. In this magnified 

 view the lighter parts of the drawing represent the delicate exposed membrane 

 of the wing, while in the rest of the figure it is covered with scales, which are 

 of a rich brown hue, partially overlapping each other in regular rows. The 

 several lines of dark spots that cross the membrane of the wing are the places 

 where the stalks of the feather were fastened to its surface. The breadth of 

 these spaces is the sixteen hundred and sixty-sixth part of an inch, and the 

 width of one of the scales the two hundred and fiftieth part of an inch. The 

 scales on the wings of an insect, termed the Lepisma Saccharina, are of two 

 kinds, one set being arranged as usual in rows, and the other, possessing a differ- 

 ent shape, are inserted between and over the former, fastening them firmly down 

 in their places. In some instances the scales are distributed over the membrane 

 without apparently any regular arrangement. Drawings 196 and 197 exhibit 

 magnified views of scales taken from the wing of a butterfly, known by the 

 name of the Morpho Menelaus. The color of the upper surface of its wing is 

 of a rich blue, brilliant beyond description, and vying in splendor with the purest 

 azure of the sky. The scales taken from the central portions are of a pale blue 

 tint, mingled with others that are almost black. The former are for the most 

 part wider than the latter, and measure nearly the one hundred and twentieth 

 part of an inch in length. Beneath the microscope they exhibit the appearance 

 presented in drawing 19G ; the entire surface being fluted with lines which run 

 lengthwise of the scale, and are connected together by short cross lines passing 

 between them. In drawing 198 and 199 are delineated the feathers of the 

 lead-colored Spring-tail, an active little insect about the tenth of an inch long, 



