Fig. 2
From: Locally-curved geometry generates bending cracks in the African elephant skin
Stratum corneum morphology of cracked and uncracked samples. a, b Light (a) and electron (b) microscopy of sections cut perpendicular to a crack reveal a fracture that is characterised by an alignment of the stratum corneum keratin sheets on both sides of the fracture and a very small degree of recoil. Moreover, the innermost sheets of the stratum corneum remain intact (arrowheads), probably due to their higher hydration level. c Section cut through an uncracked sample of stratum corneum, showing a morphology identical to that of cracked samples apart from the lack of material discontinuities. Dashed lines in b, c: boundary between the stratum corneum and the viable epidermis. Scale bars: a 250 μm; b 150 μm; c 100 μm
