An Air-borne Plant Virus

IN a recent issue of NATURE¹, Dr. Kenneth Smith described the virus of a new disease of plants as being ``air-borne''. The term in this connexion implies: (1) that the virus agent can escape from the tissues of the infected plant into the air under natural conditions; (2) that it is carried in the air; and (3) that the air-carried virus can infect a normal healthy plant.