Figure 2. Relationship of connective tissue cell type and blood cells. The upper
half of the figure shows the various types of connective tissue cells and emphasises
their inter-relatedness. They all arise from one single precursor cell. The lower part of
the figure shows the blood cells which arise from a single precursor cell which is
closely related to the precursor cell of the other connective tissue. The lineage of the
developing blood cells is shown in abbreviated form. [From Leeson & Leeson 3rd edn]