48 PHARMACEUTICAL BACTERIOLOGY 



189s; Semiclostridium Maassen 1905; Botulobacillus Jensen. 1909; Butryi- 

 bacillus Jensen 1909; Cellulobacillus Jensen 1909; Putribacillus Jensen 

 1909. 



Anaerobes. Often parasitic. Rods frequently enlarged at sporulation, 

 producing clbstridium or plectridium forms. 



The type species is Clostridium butyricum Prazmowski. 



Organisms Intermediate Between Bacteria and Protozoa 



SpirochcBtacece. Swellengrebel, 1907. — Free living or parasitic spirilli- 

 form organisms with or without flagella, with undulating or rigid spiral 

 twists. Reproduction by transverse division and by "coccoid bodies," 

 the equivalent of spores. 



Four genera are recognized as follows: 



1. Spirochata. Ehrenberg. — Non-parasitic, with flexible undulating 

 body and with or without flagelliform tapering ends. Common in sewage 

 and foul waters. 



The type species is Spirochata plicatilis Ehrenberg. 



2. Cristispira. Gross. — Giant forms with undulating body and pecul- 

 iar flattened ridge erroneously called an " undulating membrane " which 

 runs the length of the body. Parasitic in molluscs. 



The type species is Cristispira balbianii Certes, from the crystalline 

 style of the oyster. 



3. Saprospira. Gross. — ^Non-parasitic forms similar to Cristispira, 

 but without the flattened ridge or "crista" which is, if present, here 

 replaced by a straight columella or thickening of the periplast. 



The type species is Saprospira grandis Gross. 



4. Treponema. Schaudinn. — ^Parasitic and frequently pathogenic 

 forms with undulating or rigid spirilUform body. Without crista or 

 columella. With or without flagelliform tapering ends. 



The type species is Treponema pallidum Schaudinn. 



I. Artificial Key to the Orders of the Schizomycetes 



Cells united during the vegetative stage into a 



pseudoplasmodium A. Myxobacteriales 



Cells not forming a pseudoplasmodium 



Cells free or united in elongated filaments, often with a well-defined 

 sheath. Conidia frequently formed. Free sulphur, iron or bacterio- 

 purpurin often present. 



Cells typically containing granules of sulphur or bacterio-purpurin or 



both B. Thiobacteriales 



Sulphur and bacterio-purpurin absent; iron often 



present C. Chlamydobacteriales 



