. Animal locomotion or walking, swimming, and flying : with a dissertation on aëronautics. s at the root of the wing; the anterior ner-vure occupying a higher position than that further back, as inthe leaves of a fan. The spiral arrangement occurring atthe root extends also to the margins, so that wings which foldup or close, as well as those which do not, are twisted uponthemselves, and present a certain degree of convexity on theirsuperior or upper surface, and a corresponding concavity ontheir inferior or under surface; their free edges supplyingthose fine curves which act with such efficac
. Animal locomotion or walking, swimming, and flying : with a dissertation on aëronautics. s at the root of the wing; the anterior ner-vure occupying a higher position than that further back, as inthe leaves of a fan. The spiral arrangement occurring atthe root extends also to the margins, so that wings which foldup or close, as well as those which do not, are twisted uponthemselves, and present a certain degree of convexity on theirsuperior or upper surface, and a corresponding concavity ontheir inferior or under surface; their free edges supplyingthose fine curves which act with such efficacy upon the air,in obtaining the maximum of resistance and the minimumof displacement; or what is the same thing, the maximumof support with the minimum of slip (figs. 92 and 93).1 Kirby and Spenee. vol. ii. 5th ed., p. 352. 174 ANIMAL LOCOMOTION. The wings of insects can be made to oscillate within givenareas anteriorly, posteriorly, or centrally with regard to theplane of the body; or in intermediate positions with regard toit and a perpendicular line. The wing or wings of the one d e. Fig. 93. Fig. 92.—Right wing of Beetle (Goliathus micans), dorsal surface. This wingsomewhat resembles the kestrels (fig. 61, p. 136) in shape. It has an ante-rior thick margin, d e f, and a posterior thin one, b a c. Strong nervuresrun along the anterior margin (d) until they reach the joint (e), where thewing folds upon itself during repose. Here the nervures split up anddivaricate and gradually become smaller and smaller until they reach theextremity of the wing (/) and the posterior or thin margin (b); other ner-vures radiate in graceful cuives from the root of the wing. These alsobecome finer as they reach the posterior or thin margin (c a), r, Root ofthe wing with its complex compound joint. The wing of the beetle bearsa certain analogy to that of the bat, the nervures running along the anteriormargin (d) of the wing, resembling the humerus and forearm of the bat (, d, p. 175), th
Size: 2251px × 1110px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubje, booksubjectphysiology
