Left column: observed cumulative 3.6-μm (upper panel) and 4.5-μm (lower panel) counts for the various types of objects (as classified by visual inspection) and their total number (solid line). Middle and right columns: cumulative model counts for the hierarchical (middle) and monolothic (right) models. The counts are reported here for the various different morphological classes as indicated in the line caption. Note that monolithic and hierarchical scenarios only differ in the spheroid (and therefore also total) counts.