By means of electron microscope and ultra-thin section technic, the author studied how the bacterial structure, which were described in Part I, changed with the process of multiplication, and obtained the following resules: 1) In B. anthracis, the nuclear site divides into two parts with narrowing of the middle part of bacterial cell; the cell wall coresponding to the dividing part of the nuclear site thikens and develops towards the center of the bacterial cell forming the so-called transverse cell wall; the completed transverse cell wall thickens and shows double layer structure; then the cell completely divides into two cells. 2) The cell division precess of B. subtilis is the same as that of B. anthracis. 3) In B. diphtheriae, some differences were observed; the cell wall corresponding to the dividing part of the nuclear site was slightly swollen, and the transvers cell wall formed there had the double layer structure from the biginning of its formation. 4) In Staph. aureus, the cell division process was nearly the same as that of B. anthracis, except the fact that the second transverse cell wall was formed in the vertical direction to the first one.