INCREASED VIRULENCE OF THE HOG-CHOLERA BACILLUS PRODUCED BY PASSAGE THROUGH RABBITS.

By passage through a series of eleven rabbits a culture of the hogcholera bacillus has increased its virulence a thousand times. A subcutaneous injection of twenty organisms, or 0.00000001 cc. of a 24 hour bouillon culture, or a drop of a bouillon culture rubbed lightly into the shaven skin, produces, in the rabbit, a characteristic disease resulting in death on or about the 6th day.