Figures, living Metschnikoff cell, Ascetta clathrus and Sycon raphanus [sponge] by George Bidder Four plates of magnified anatomical figures showing 'Living Metschnikoff cell, focussed through the ectoderm', 'Section through the wall of Ascetta clathrus', 'Section through the greater part of the length of an afferent pore in Ascetta clathrus' and 'Basal spherules of collar cells, Sycon raphanus.' Subject: Zoology / Marine biology Prints of these figures were published in volume 51 of the Proceedings of the Royal Society alongside the paper 'Note on excretion in sponges'. 1892