The Adhesion of the Barnacle,Balanus Balanoides,to Slate Surfaces

Techniques were developed to measure the adhesion of the barnacleBalanus balanoides(L.), over the post metamorphosis period. It was found thatBalanus balanoidesis capable of producing a proteinaceous adhesive material within one day of metamorphosis. This adhesive material was found to withstand applied forces of 1·7×105Nm−2before cohesive failure took place. The strength of the cement produced by older barnacles, measured at a time when the adult cement apparatus is known to be operating, was considerably greater and applied forces of 9·3 × 10 Nm were necessary to induce cohesive failure in the cement. The strength ofB. balanoidescement was thus shown to be at least one tenth of that of commercial adhesives which have tensile strengths in the region of 107Nm−2.