38 PHARMACEUTICAL BACTERIOLOGY 



I. The Classification by Migula 



BACTERIA OR MICROBES 



(Schizomycetes or Fission Fungi) 



I. Family Coccace^. — Micrococci. Cells globular or not elongated. 

 Division in two or three directions of space. Spore formation rare. 



1. Micrococcus. — Cells spherical or biscuit-shaped. Division in one 

 direction of space. With or without flagellae. A large genus, represented 

 by numerous species, pathogenic and non-pathogenic, chromogenic, zymo- 

 genic, etc. 



2. Streptococcus. — Generic limitation not clearly defined. Often 

 merely chain forms of above, resulting from cohesion of cells dividing in 

 one direction of space. 



3. Sarcina. — Division in three directions of space. Cells often in fours 

 (Tetracoccus) — as for example, the sarcina of the stomach. With or with- 

 out flagellae. 



II. Family Bacteriace^. — Bacilli. Cells more or less elongated, 

 cylindrical, straight; some are somewhat curved or irregular in outUne. 

 With or without flagellae. Endospore formation. Transverse septation. 



1. Bacillus. — Variable in size and length of cell. Numerous flagellae. 

 Endospore formation common. A very large group, to which belong many 

 of the most important microbes. Includes the old genus Bacterium. 



2. Pseudomonas. — Said to have only polar flagellas. Doubtful genus, 

 by many relegated to the group bacillus. 



III. Family Spirillace^. — Spirillae. Cells elongated and spirally 

 twisted. Transverse septation. Body fixed, with polar flagellae. 



1. Spirillum. — Numerous polar flagellae. Large group. 



2. Microspira. — Few polar flagellae. A group Spirosoma is said to be 

 without flagellae. 



IV. Family SpiROCHETACEiE. — Spirocheta. Long, single-celled, flex- 

 ible, spirally twisted threads without flagellae. One genus — Spirocheta. 

 (Some authorities place these organisms in the animal kingdom with the 

 Protozoa.) 



V. Family Mycobacteriace.e. — Filamentous organisms, perhaps 

 forming a connecting link between bacteria proper and the lower filamen- 

 tous fungi. Cells filamentous but not enclosed in a sheath. To this 

 family belong the groups Mycobacterium and Actinomyces (ray fungus). 

 No flagellae have been observed. Mostly transverse septation. Gonidial 

 (spore) formation has been observed. 



VI. Family CHLAMYDOBACTERiACEiE. — ResembHug above family, but 

 the cell filaments are enclosed in a sheath. The following not very clearly 



