Dutra (1948) noted that in some cases, clasmatocytes
(macrophages) could be seen surrounding fibrinoid material in alveoli, and these cells were sometimes fused to form multinucleated giant cells; others also noted occasional giant cells (Freiman and Hardy 1970).
It is believed that the sources of the mononuclear exudate cells are, on the one hand, the "resting wandering cells" of Maximow(6) [the "clasmatocytes" of Ranvier, the "histiocytes" of Aschoff and Kiyono(7) and Kiyono(8)]; on the other hand, the endothelium of the common blood vessels, to which an important r61e is attributed.
According to Herzog and Marchand,(11) the so-called adventitial clasmatocytes (histiocytes) are the most important elements.
A part arises through the mobilization of the local resting wandering cells (clasmatocytes, histiocytes) of the connective tissue; another part comes from the blood and represents hematogenous, emigrated lymphocytes and monocytes.
HISTIOCYTES OR RESTING WANDERING CELLS (CLASMATOCYTES)
Marchand,(23) who previously in his papers dealing with the inflammatory changes of the omentum described only one type of "adventitial cells" or "clasmatocytes" near the capillaries, elements which are now known to belong to the phagocytic and dye-storing cell type of the histiocytes, at the present time,(11) under the influence of the investigations of his student Herzog,(24) distinguishes two cell types accompanying the capillaries.
However, this phenomenon, at least in the stages mentioned, is not as prominent as in the subcutaneous tissue; and, correspondingly, the majority of the polyblasts in the tissue are of local origin--mobilized histiocytes (resting wandering cells or clasmatocytes. Figs.