MODE OF MULTIPLICATION 71 



the clusters in which these organisms are commonly seen. 

 (See Fig. 2, a.) With the streptococci, however, the ten- 

 dency is for the segmentation to continue in one direction 

 only, resulting in the production of long chains of 4, 8, and 

 12 individuals. (See Fig. 2, 6.) 



The sarcinse divide more or less regularly in three direc- 

 tions of space; but instead of becoming separated the one 

 from the other as single cells, the tendency is for the seg- 

 mentation to be incomplete, the cells remaining together 

 in masses. The indentations upon these masses or cubes, 

 which indicate the point of incomplete fission, give to the 

 bundles of cells the appearance commonly ascribed to them, 

 viz., that of a bale of cotton or a packet of rags. (See Fig. 

 2>e.) 



The mode of multiplication of bacilli is similar to that 

 of the micrococci i. e., a dividing cell elongates slightly in 

 the direction of its long axis; an indentation appears about 

 midway between its poles, and this becomes deeper and 

 deeper, until eventually two daughter-cells have formed. 

 This process may occur in such a way that the two young 

 bacilli adhere together by their adjacent ends in much the 

 same way that sausages are seen to be held together in 

 strings (Fig. 3, /), or the segmentation may take place more 

 at right angles to the long axis, so that the proximal ends 

 of the young cells are flattened, while the distal extremities 

 may be rounded or slightly pointed (Fig. 3, e). The segmen- 

 tation of the anthrax bacillus, with which we are to become 

 acquainted later, results, when completed, in an indenta- 

 tion of the adjacent extremities of the young segments, so 

 that by the aid of high magnifying powers these surfaces 

 are seen to be actually concave. Bacilli never divide longi- 

 tudinally. 



