Aspects of free cells in the coelomic fluid of newts have been studied before and after treatments of such irritants in vivo as ; 1) daily injection of a hypotonic solution, 2) daily injection of a isotonic saline solution, and 3) a single injection of 10% PHA-M solution. When the peritoneal cavity recieved any of these stimuli, the relative proportions of most free cells in the cavity varied. Granulocytes rapidly and remarkably increased due possibly to the reflection of physiological changes of the host animal after the treatment.
Cellular responses to PHA-M were positively occurred in lymphocytes and monocytes, which indicated the mitotic initiating agent was proved to has the same effect to free cells in vivo as cultured lymphocytes in vitro.
Mitotic activities of monocytes and lymphocytes in, vivo have been raised by the PHA-injection up to about 1 per cent within 24 hours of treatment. Characteristic cells with Russell's bodies have not been directly affected by a mild irritant or a mitogenetic agent.