In Euplotes a replication band of the macronucleus has larger heterochromatin masses on one side of the band after DNA replication has occurred. The replication band moves in the direction of lighter staining in the macronucleus. Vacuoles containing concretion bodies are observed. TEM taken on 8/03/67 by R. Allen with Philips 200 operating at 60kV. Neg. 7,200X. Bar = 1µm. Standard glutaraldehyde fixation followed by osmium tetroxide, dehydrated in alcohol, and embedded in an epoxy resin. Microtome sections prepared at approximately 75nm thickness. A print of the negative was scanned and processed in Photoshop. This image is best used for qualitative analysis. Another image (CIL:38871) is available for quantitative analysis. Additional information is available at (http://www5.pbrc.hawaii.edu/allen/).