CHAPTER XXVI. 
TREPONEMATA, SPIROXEMATA, LEPTOSPIRATA, 
SPIROCH^TA AND SPIRILLA. 
Treponema pallidum. 
Treponema pertenue. 
Spironema refringens. 
Spironema phagedenis. 
Spironema recurrentis. 
Spironem.\ novyi. 
Spironem.\ carteri. 
Spironema duttoni. 
Leptospira icteroh.emorrhagi^. 
Leptospira icteroides. 
Leptospira hebdomadis. 
Spiroch.eta morsus-murium. 
Spirillum fusiformis. 
Fusiform bacilli. 
The classification of these organisms, which prior to 1905 were 
grouped in the Ehrenberg genus Spirochseta (1S34), has been greatly 
confused through their appellation by a number of terms which are 
not in accord. This is partly due to the rapid accumulation of import- 
ant members of this type, and also to conflict of the names given to 
them with the rules of priority' which govern the designations of 
botanical and animal species. E^'idence at present available indicates 
that those organisms w^hich would be included in the old genus Spiro- 
chneta are not related to the Protozoa, but are members of the great 
family of the Bacteria; hence, the rules of botanical nomenclature 
should be followed in their terminology. It is particularly desirable 
to avoid a succession of names for the same organism. The most 
important known member of the group is the inciting agent of syphilis. 
It was originally named Spirochai'ta pallida by Schaudinn, and then, 
according to Dobell,^ serially designated Spironema pallidum by 
A'illemin early in 1905, Treponema pallidum by Schaudinn later in 
the same year, and still later in 1905 called Microspironema pallidum 
by Stiles and Pfender. It would appear from present information 
that the proper name for the sv-philitic microbe therefore is Spironema 
pallidum, according to the rules of botanical terminology. 
Xoguchi' has proposed a new classification of those bacteria of the 
spirochjeta type which are of medical importance. 
Classification of Noguchi. 
Name. 
Spironema 
Treponema 
Leptospira 
Diameter. 
. 35-0 . 50 
. 25-0 . 30 
0.25-0. 30 
Length. 
8-16 
6-14 
7-14 
Axial 
filament. 
Membrane. Flagellum. 
' Medical Research Committee, Special Report Series, 191S, No. 19. 
- Jour. Exp. Med., 1918, 27, 575. 
