Further observations on the secretory cells in the optic tentacles of Helix, with special reference to the results of vital staining

Abstract

ABSTRACT When the collar cells or the lateral cells in the tentacles of Helix aspersa are stained with neutral red and other vital dyes, uptake of the dyes occurs chiefly in the lipoidal β-bodies. Janus green B and dahlia are taken up by the mitochondria. In vitally-coloured preparations, no ‘peri-nuclear bodies’ are present in the collar and lateral oval cells, such as were previously found in these cells after post-osmication for 14 days. Fixed preparations of similar cells, post-osmicated for different periods, indicate that the peri-nuclear dictyosomes are artifacts due to over-impregnation with osmium. In addition to the lateral oval and lateral processed cells, which lie at intervals along the inner surface of the dermo-muscular sheath in Helix, unicellular calcium glands are found, lying immediately beneath the epithelial surface; these are far more numerous in H. pomatia than in H. aspersa. They contain granules of a calcium salt suspended in a matrix of mucopolysaccharide, and apparently produce the whitish mucoid secretion that is extruded on to the surface of the tentacles when the animal is disturbed. There is no evidence to suggest that the lateral cells are concerned in the production of this mucoid secretion.