SPORE-FORM A TION. 5 7 



the parent from which they sprang, or they will remain 

 together for a time as diplococci ; the surfaces now in 

 juxtaposition are flattened against one another, and not 

 infrequently a fine, pale dividing-line may be seen 

 between the two cells. (See Fig. 2, c and d.) A similar 

 division in the other direction will now result in the 

 formation of groups of fours as tetrads. 



In the formation of staphylococci such division occurs 

 irregularly in all directions, resulting in the production 

 of the clusters in which these organisms are commonly 

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

 the tendency 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, b.) 



The sarcinse divide more or less regularly in three 

 directions of space ; but instead of becoming separated 

 the one from the other as single cells, the tendency is 

 for the segmentation to be incomplete, the cells remain- 

 ing 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 com- 

 monly 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 indenta- 

 tion 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 



