Tetrahymena cells that are not forming a digestive vacuole often have a tube-like extension of the cytopharyngeal membrane attached to the deep fiber that extends several microns into the cytoplasm. The acidosome-like vesicles are docked at this membrane tube. TEM taken on 2/12/71 by R. Allen with Hitachi HU11A operating at 75kV. Neg. 16,250X. The raw negative was scanned with an Epson Perfection V750 Pro and this high resolution image is best used for quantitative analysis. Additional information available at (http://www5.pbrc.hawaii.edu/allen/).