Size and granularity of cells in each of the HLO. (A) Peripheral blood (PB), (B) spinal bone marrow (SBM), (C) ilial bone marrow (IBM), and (D) spleen all have large populations of granular cells. These populations were not seen in the (E) mesenteric lymph nodes or (F) thymus, which contain only populations with less granularity. (G) We assessed the percentage (mean ± SEM) of high side-scatter (granular) cells in PB, SBM, IBM, and spleen.