. The Wilder quarter-century book: a collection of original papers dedicated to Professor Burt Green Wilder at the close of his 25th year of service in Cornell University (1868-1893). Wilder, Burt G. (Burt Green), 1841-1925; Zoology; Anatomy; Physiology; Evolution; African Americans. 64 John Henry Comstock tirely wanting. Sometimes, as in Danais, remnants of the basal part of the branches of media project back into the dis- cal cell from the discal vein (Fig. 13) ; while in many other butterflies the branches of media are so completely united with radius and cubitus that there is no indication
. The Wilder quarter-century book: a collection of original papers dedicated to Professor Burt Green Wilder at the close of his 25th year of service in Cornell University (1868-1893). Wilder, Burt G. (Burt Green), 1841-1925; Zoology; Anatomy; Physiology; Evolution; African Americans. 64 John Henry Comstock tirely wanting. Sometimes, as in Danais, remnants of the basal part of the branches of media project back into the dis- cal cell from the discal vein (Fig. 13) ; while in many other butterflies the branches of media are so completely united with radius and cubitus that there is no indication of the fact that they do not belong to these systems of veins (Fig. 14). It is probable that in none of the Palceodictyoptera were the wings plaited, as they are in many existing insects ; although. Fig. 13.—Fore wing of Danais. in some, they were broadly folded. And if we except the anal furrow (vein VIII), already referred to, all of the veins were of the type that is termed convex ; that is, they were more prominent on the upper surface of the wing than on the lower. We thus see that the evidence of the Palseodictyoptera does not corroborate the theory of Adolph and Redtenbacher as to the primitive type of the wings of insects. Instead of the primitive wing consisting of regularly alternating concave and convex veins, as described by them, it is probable that the concave veins are a later development, either arising de novo ox being modified convex veins, excepting always the anal fur- row (vein VIII), regarding the origin of which we know nothing. Concave veins have evidentlj^ arisen to meet two distinct needs: first, in those insects in which the wings have become. 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 Wilder, Burt G. (Burt Green), 1841-1925. fmo; Jordan, David Starr, 1851-1931. ins; Comsto
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