848 PATHOGENIC MICROORGANISMS 



mollusca. The term was first proposed by Gross 5 iA 1910. A type 

 of these organisms is found in oysters (Spirochaeta balbianii (Certes, 6 ) 

 1882). Another genus of the same order, Saprospira, was found 

 by Gross to exist in mussels. 



None of these are pathogenic for higher animals. They are char- 

 acterized by the presence of a membraneous structure which resembles 

 a crista or ridge which runs spirally along the entire length of 

 the body. The body is chambered, that is, transverse bands seem 

 to show along its entire length. There are no terminal filaments 

 and there seems to be a strong flexible membrane. Reproduction, 

 according to Gross, takes place by multiple transverse fission or 

 sporulation, but Noguchi has failed to confirm the occurrence of 

 sporulation. 



II. Spironema and Treponema. This is a large group of parasitic 

 spiral organisms which are commonly spoken of as the "spirochete" 

 in medical nomenclature. The characteristic feature of these is a 

 spiral flexible body with terminal filaments, but no undulating mem- 

 brane. They may apparently multiply by transverse as well as by 

 longitudinal fission. They move by an undulating movement, a few 

 of them, however, retaining their regular curves during motion. 

 Dobell in an address before the Royal Society in 1912 expressed the 

 belief that the word treponema should be used for all of the small 

 parasitic varieties. Noguchi believes with Gonder that the term 

 treponema should be restricted, as was done by Schaudinn, 7 to those 

 varieties having great constancy of curves, while spironema should be 

 applied to those with less constant curves, but he, nevertheless, classi- 

 fies them together under the same main heading since he believes 

 they are closely related. 



In this class belong the Treponema pallidum of syphilis and the 

 Treponema or Spirochcete pertenue of Yaus. The class also includes 

 the organisms of relapsing fever, a number of parasites found in 

 rodents, such as the well known organism which invades apparently 

 normal mice (and was once falsely looked upon as the cause of cancer 

 in mice) and various saprophytic types found in the mouth, intestine 

 and genital mucous membranes, such as the Treponema calligyrum 



6 Gross, Mitt. zool. Station Neapel., 1910-13, 20, 41 and 188, Cent. f. Bakt., 

 Orig., 65, 1912, 83. 



Certes, Bull. Soc. zool. franc., 7, 1882, 347. 



7 Schaudinn, Deut. med. Woch., 43, 1909, 1728, Arb. a. d. k. Gesundhst., 1904. 



