The adhesion of treefrog toe-pads to glass: cryogenic examination of a capillary adhesion system

Abstract

Treefrog adhesive toe-pads in contact with a glass surface were examined with scanning electron microscopy after preparation of the specimens using cryogenic methods. Frozen two-pads lost all adhesive abilities, which may be ascribed to the freezing and cold contraction of the intermediary fluid found between the toe-pad and the substrate. Residue from this fluid remained behind on both toe-pad and the substrate. Impressions of toe-pad epithelial cells in the residue indicate that the individual cells may be relatively free to find their own closest contact with the substrate. The results corroborate earlier models indicating the importance of the intermediary fluid in a capillary adhesion system.