barc^m4-2 somatic clones of both type I and type II neuroblast lineages exhibit a significant decrease in the total number of cells compared to controls. Type II neuroblast lineage clones are mostly composed of intermediate neural progenitors and comparatively few neurons, but exhibit no significant difference in the total number of intermediate neural progenitors per clone, as compared to controls; these clones exhibit a significant increase in the number of immature Ase-positive, Dpn-negative intermediates and, conversely, a significant decrease of Ase-positive, Dpn-positive, as compared to controls. Type I neuroblast lineage clones exhibit a significant increase in the number of ganglion mother cells, as compared to controls.