“…The main sites of these cells are to be found in the lymph glands, spleen, bone marrow, liver, suprarenal and pituitary. In the skin the primitive mesenchymal cells can be shown to exist in the dermis around the adventitial glands and hair follicles and between the collagen bundles (Robb‐Smith, 1944). In Hodgkin's disease there is a stimulus, the origin of which is still unknown, which induces the primitive mesenchymal cell to undergo uncontrolled proliferation so that it may develop into any of the blood cells, into reticulum cells or further into giant cells of the Dorothy Reed type.…”