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*CIL – Cell Image Library accession number. Please use this to reference an image.

CIL:39157*  Cite 

Detail of the junction between the ribbed wall and the right side of the cytopharynx area. The ribbed wall is covered by alveoli and the ribs are produced by small narrow ridges similar to the larger ridges covering the whole cell body. Two arrays of microtubules are present in this zone, clumps of hexagonally packed bundles lying under the ridges and rows of microtubules that lie under the single cytopharyngeal membrane. There is some suggestion that these rows of microtubules may associate together to form the bundles. Tips of cilia in cross section give 4 views of how the tips of cilia end, the 9-doublet first become 9 singlets and then these are lost one by one leaving only the two central singlets at the tip of a cilium. Sections of the cytostomal cord are also present under the rib wall. This is the cord that wraps around the cytopharynx. TEM taken on 7/27/73 by R. Allen with Hitachi HU11A operating at 75kV. Neg. 23,000X.

Technical Details

Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections prepared at approximately 75nm thickness. 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 (

Biological Sources
NCBI Organism Classification
Paramecium caudatum
Cell Type
cell by organism
eukaryotic cell
Eukaryotic Protist
Ciliated Protist
Cellular Component
oral apparatus
Biological Context
Biological Process
oral apparatus organization
Richard Allen (University of Hawaii)
Digital Object Identifier (DOI)
Archival Resource Key (ARK)
Grouping This image is part of a group.
Image Type
transmission electron microscopy (TEM)
illumination by electrons
Image Mode
detection of electrons
Parameters Imaged
electron density
Source of Contrast
stain with broad specificity
Visualization Methods
stain with broad specificity
uranyl salt
lead salt
osmium tetroxide
Processing History
recorded image
unprocessed raw data
Data Qualifiers
raw, unprocessed data
suitable for spatial measurements
Spatial Axis Image Size Pixel Size
X 3256px 0.87nm
Y 3767px 0.87nm