The development of filter‐passing organisms in Corynebacterium fascians cultures

SUMMARY Viable filter‐passing particles have been obtained from gall‐tissue cultures of Corynebacterium fascians. On gelatine media filtrates of the cultures first produced a faint clouding of the liquefied gelatine; this was due to masses of granules of very variable size. In some cultures further development took place, the next phase being the appearance of diplococci. Sometimes the coccal stage persisted but occasionally complete regeneration of the normal C. fascians type rod finally ensued. This sequence of growth follows the pattern designated as the ‘L phase’, occurring in the life‐history of certain bacteria. Growth of L forms probably occurs in Agrobacterium tumefaciens also.