Vegetative cells ofBacillus megaterium formed protoplasts in a sucrose-stabilized medium under the influence of lysozyme. The protoplasts sporulated during subsequent incubation. The morphological properties, germination, resistance to u. v. irradiation and thermo-resistance of protoplast spores were the same as with normal cells. It thus appears that in the later sporulation stages the spore formation occurs, without participation of the sporangium cell wall.