A high resolution image of the micronucleus and macronucleus of Opercularia coarctata. The nuclear envelope has numerous pores, at least as many per unit length as in the macronucleus. Some areas of the outer membrane of the micronucleus envelope bare ribosomes. TEM taken on 6/11/69 by R. Allen with Philips 300 operating at 60kV. Neg. 23,200X. The raw film was scanned with an Epson Perfection V750 Pro. this image is suitable for quantitative analysis. 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/).