proliferation. Cell-genesis, reproduction.

pronation. The act of rotating the forearm in such a way that the palm of the hand looks backward when the arm is in the anatomic position, or downward when the arm is extended at a right angle with the body. (Stedman.)

prophylactic. Preventing disease.

protargol. A combination of silver with a proteid base.

protean. Having the power to change form.

protonuclein. A preparation from the lymphoid tissue of animals.

protoplasm. Primitive organic cell matter.

protuberance. A projecting part.

pseudo. Prefix, signifying false.

ptomain. A crystallizable nitrogenous basic substance, produced by bacteria in dead animal or vegetable matter.