An image of the nucleoli of the macronucleus. Nucleoli have a core of DNA that contains the genes that are transcribed into ribosomal RNA. Assembly of the ribosomal subunits from this processed RNA and from proteins transported into the nucleus through the pores occurs in the nucleoli. A concentric stack of rough ER encircles a mitochondrion. TEM taken on 8/16/67 by R. Allen with Philips 200 operating at 60kV. Neg. 7,200X. Bar = 1µm. The negative was printed to paper and the image was scanned to Photoshop. This digitized image is available for qualitative analysis. An unprocessed, high resolution version of this image (CIL:34537) is in the library and available for quantitative analysis. Additional information available at (http://www5.pbrc.hawaii.edu/allen/).