It is remarkable that these little segregated areas of nucleolar constituents look so consistently like “pop ups” that have a predetermined location, density, relative size, and texture.  I don’t believe that it is known what these early blips on the surface of the nucleolus are, (not including the blips that have the substructure notable of cajal bodies) though these may be precursors or similar structures. The banding (linear beads on a string appearance as if wrapped in a ball) in these bodies (by reason of tissue preparation or observer bias –shown in these three micrographs) would not qualify as cajal bodies. So what are they.  The bodies I am speaking of are all pointing upward like little volcanos (especially on the left)  with elements coming or going… whichever haha. Two images on right are slightly more electron dense than the adjacent nucleolar elements.

These images are from scattered micrographs, though two are from 14CoS hepatocytes which had never had or been withdrawn from NTBC.