SPIROCH/ETES. 



A REVIEW OF RECENT WORK. 



SECTION I. 



GENERAL CHARACTERS OF SPIROCH^TES. 

 BIOLOGICAL POSITION OF SPIROCH/ETES. 



The name Spirochaeta was first invented by Ehren- 

 berg in 1833 for the organism discovered by him and 

 named Spirochceta plicatilis. It was regarded by him 

 as a protozoon, but its relationship to other members of 

 this order was not clearly determined; and while some 

 writers considered that spirochaetes were members of 

 the class Trypanosomidae, others regarded them as 

 really bacteria. Indeed, in some of the earlier text- 

 books of bacteriology the term spirochaete was applied 

 to a number of spirillar forms. 



The great increase of interest which has recently been 

 aroused in the spirochaetes dates from the discovery by 

 Schaudinn in 1905 of the spiral organism associated 

 with syphilis, which he assigned to this class. The 

 attention thus directed to these minute organisms has 

 resulted in the discovery of a large number of forms, 

 some associated with conditions of disease, others living 

 apparently as harmless saprophytes. Among the latter 

 must be classed the large varieties present in several 

 genera of shell-fish. 



The relationship existing between the larger and the 

 smaller spirochaetes has not been thoroughly eluci- 



