A Cytological Study of the Cement Apparatus of the Barnacle, Chelonibia Testudinaria Linnaeus, an Epizoite on Turtles

The cytology of Chelonibia testudinaria cement cells showed the mature cells to be polarised. Accumulated secretory (cement) granules are found at the pole of the cell where the duct makes connection, whilst at the opposite pole aggregated granules of a different kind are found. These latter granules are lysosomes, residual bodies; the contents of the residual bodies (proteins and lipofuscin) are the end-products of selective autophagy. Lysosomes, residual bodies, were also observed in the cement cells of two other epizoic barnacles found at Beaufort, North Carolina.