A high resolution micrograph of the locomotor cortex of Didinium. A longitudinal section reveals the basal bodies and the axonemes of cilia as they emerge from the cell cortex of Didinium. Bundles of microtubules extend from the basal bodies into the endoplasm through the fibrous layer that characterizes the cortex of Didinium. Tubular or flattened early endosomes with coated pits at their margins are present in the endoplasm beneath the fibrous layer. Mitochondrial cristae appear to be decorated by F1F0 ATP synthases. Cross sections of three bacteria are noted between the cilia. TEM taken on 5/9/69 by M. Sage with Philips 300 operating at 60kV. Neg. 14,800X. The raw film was scanned with a Nikon Coolscan 9000ED. Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol and embedded in an epoxy resin. Microtome sections prepared at approximately 75nm thickness. Additional information available at (http://www5.pbrc.hawaii.edu/allen/).