4 BACTERIOLOGY 



capsulatus mucosus of Fasching, are furnished with cap- 

 sules. By coalescence of the cell-capsules conglomerations 

 of cells are formed which are called zooglcea, and may 

 spread over the surface of fluids in the form of a pellicle. 

 This pellicle sometimes serves to distinguish between 

 micro-organisms which strongly resemble each other for 

 instance, cholera bacilli form a pellicle, whereas Finkler- 

 Prior bacilli do not. 



Multiplication of bacteria takes place by fission, hence 

 their name of Schizomycetes, or ' fission-fungi.' As soon as 

 the individual organism has attained its normal size, there 

 appears in the centre a clear line which forms the sign of 

 division, the two individuals so produced then breaking free 

 from one another and forming again independent or- 

 ganisms. If, however, the daughter-cells do not become 

 disjoined, groups are formed in which the cells remain 

 connected in strings, in clusters (staphylococci), in chains 

 (streptococci), and so on, the spiral strings formed by 

 the vibriones being often wrongly described as spirilla. 

 If the division of cocci takes place in one direction of 

 space, diplococci are formed ; division in two directions 

 yields as a result tablet-cocci (merismopedia, tetracocci) ; 

 while division in three directions gives packet-cocci or 

 sarcinae. 



A second mode in which bacteria propagate is multi- 

 plication by the development of spores. These are dis- 

 tinguished by their very remarkable power of resisting the 

 influences of temperature and the action of chemicals, and 

 are therefore called also permanent forms. The spores in 

 most cases occupy a position in the centre of the bacterial 

 cell, but in a few varieties they are at trie end. Sometimes 

 they cause a bulging of the centre of the cell, so that the 

 latter becomes spindle-shaped, a form which is known as 

 clostridium (see fig. 1). In the cases in which they 



