These are the most numerous of all of the leucocytes. Their size varies significantly, the older cells being somewhat smaller than the newer cells because of the loss of cytoplasm from the older cells. The nucleus size is the same in all cells but may be kidney shaped in some cases. The mobility of these cells is greatly reduced and their phagocytic action is probably nil. Their function is thought to be that of regulating toxic materials. They also release enzymes that assist in the synthesis of nucleoplasm. In their degeneration they release special compounds called gamma globulins that have antibody properties.