. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. 355 summit, where it is continuous with the overlying corneal facet (fig. 2, ps. c). In Vespa during part of the pupal stage, the cone cells lie at the bottom of a considerable depression, and their outer ends are conspicuously pointed, as in Belostoma. Over the ommatidia, are faintly stained, rounded bodies which I formerly mistook for nuclei of the corneagen (fig. 3, p. s. c). But further study shows they are chitenous bodies secreted by the cone cells and that they probably correspond to the pseudocone in Tabanus and Belos
. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. 355 summit, where it is continuous with the overlying corneal facet (fig. 2, ps. c). In Vespa during part of the pupal stage, the cone cells lie at the bottom of a considerable depression, and their outer ends are conspicuously pointed, as in Belostoma. Over the ommatidia, are faintly stained, rounded bodies which I formerly mistook for nuclei of the corneagen (fig. 3, p. s. c). But further study shows they are chitenous bodies secreted by the cone cells and that they probably correspond to the pseudocone in Tabanus and Belostoma,. Fig. 1. Semidiagrammatic view of an ommatidium of Belostoma. Fig. 2. Same, of Tabanus. Fig. 3. Same, of young pupa of Vespa: A—D. Cross sections of ommatidium and points whence they were taken, a—c. Same of T a b a n u s. E. Semidiagrammatic view of cone cells in an old Hymenopterous pupa, , axial nerve bundle, , crystalline cone cells, , incipient corneagen. g^~'^, incipient ganglion cells, »i, nerve branch, , optic pit. , ommatidial spine, , cuticular tube, formed by circle of cells around the ommatidium. 2^ 9-^ primary pigment cell, , pseudocone. , rudi- mentary hairs on cone cells, t., trachea. The presence of these hair-like pseudocones over the cone cells of Belostoma, Tabanus and Vespa cannot but awake the sus- picion that the ommatidia are modified hair-bearing organs, and this suspicion is fully confirmed by the fact that, in the young pupae of Vespa, the first corneal cuticula is actually provided with hair-like spines unquestionably formed by the hardening of the outer ends of 25*. 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 Anatomische Gesellschaft. Jena : G. Fischer
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