Identifier: animallocomotion00pett (
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Animal locomotion or walking, swimming, and flying : with a dissertation on aëronauticsYear:
1873 (
1870s)Authors:
Pettigrew, James Bell, 1834-1908Subjects:
Animal locomotion Physiology AeronauticsPublisher:
London : Henry S. King & Co.Contributing Library:
Yale University, Cushing/Whitney Medical LibraryDigitizing Sponsor:
Open Knowledge Commons and Yale University, Cushing/Whitney Medical LibraryView Book Page:
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view book online to see this illustration in context in a browseable online version of this book.Text Appearing Before Image:omthis circumstance been named elytra, from the Greek eXvrpov,a sheath. The anterior wings are dense, rigid, and opaquein the beetles (fig. 89, r); solid in one part and membran-aceous in another in the water-bugs (fig. 90, r); more or lessmembranous throughout in the grasshoppers; and completelymembranous in the dragon-flies (fig. 91, e e, p. 172). Thesuperior or upper wings are inclined at a certain angle whenextended, and are indirectly connected with flight in thebeetles, water-bugs, and grasshoppers. They are activelyengaged in this function in the dragon-flies and butterflies.The elytra or anterior wings are frequently employed as sus-tainers or gliders in flight,1 the posterior wings acting more 1 That the elytra take part in flight is proved by this, that when theyare removed, flight is in many cases destroyed. PROGRESSION IN OR THROUGH THE AIR. 171 particularly as elevators and propellers. In such cases the elytraare twisted upon themselves after the manner of wings. Fig. S9.Text Appearing After Image:Fig. 90. Pig. 89.—The Centaur Beetle Augus&ma eentaurus), seen from above. Showselytra (r) and membranous wings (e in the extended state. The nervuresare arranged and jointed in such a manner that the membranous wings canbe folded (e) transversely across the back beneath the elytra during repose.When so folded, the anterior or thick margins of the membranous wings aredirected outwards and slightly downwards, the posterior or thin marginsinwards and slightly upwards/ During extension the positions of the mar-gins are reversed by the wings twisting and rotating upon their long axes, theanterior margins, as in bats and birds, being directed upwards and forwards,and making a very decided angle with the horizon. The wings in the beetlesare insignificantly small when compared with the area of the body. Theyare, moreover, finely twisted upon themselves, and possess great power aspropellers and elevators.—Original Fio. .0.—The Water-Bug (Genus belostoma). In this insect the superiorNote About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.