[Coloring cells of the cornea of trout].
Cells from the eye cornea of Hexagrammos octagrammus which are responsible for changes of the cornea colour from bright orange to colourless, depending on the light conditions, are described. It was shown that the change in cornea colour was due to a shift of red pigment from the cell body into its processes (in the light) and in the opposite direction at the dark adaptation of animals. The ultrastructural constitution of these cells has a number of characteristics. The whole cell cytoplasm is filled up with fine lipid droplets wherein carotenoid pigments giving red colour to these cells are presumably dissolved; the cytoplasmic membrane forms numerous deep and branched folds into the cell and has a lot of pinocytose visicles; the cell body and especially the process display many microtubes arranged regularly. The described cells differ greatly in their form, size and ultrastructural constitution from the known types of pigment cells (melanophores, xanthophores and erythrophores). This makes it possible to consider them as chromatophores of an independent type.