[ 487 ] XXVII. Remarks on the Pulvilli of Insects. By John Black-wall, Esq., F.L.S. Read, February 1, 1831. In the Physico-Theology of Dr. Derham, p. 363, note b, it is stated that " diverse Flies, and other Insects, besides their sharp hook'd Nails, have also skinny Palms to their Feet, to enable them to stick on Glass, and other smooth Bodies, by means of the Pressure of the Atmosphere." This opinion, which appears to be almost universally adopted by the entomologists of the present day, has derived additional weight from the investiga-tions of Sir Everard Home, whose papers relative to this curious subject, illustrated by figures of the parts employed in climbing, engraved principally from drawings made by Mr. Bauer, are published in the Transactions of the Royal Society for 1816. These researches are regarded by Messrs. Kirby and Spence (see their Introduction to Entomology, vol. ii,. Letter xxiii.) as having " proved most satisfactorily, that it is by producing a vacuum between certain organs destined for that purpose and the plane of position, sufficient to cause atmospheric pressure upon the exterior surface, that the animals in question are en-abled to walk up a polished perpendicular, like the glass in our windows, or with their backs downward on a ceiling, without being brought to the ground by the weight of their bodies." To dissent from a theory so generally received, including among its advocates numerous illustrious names, may, perhaps, be deemed VOL. XVI. 3r presumptuous;
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