302 GENUS SPIROCHAETA 
So, too, the passive carriage or active multiplication within the insect host, which 
Stiles ('06) regarded as a sufficient test of the plant or animal nature of spirochetes, 
only pushes the problem a step farther back, for some spirochetes, at least, multiply 
in the insect host and some trypanosomes are apparently carried and transmitted in a 
passive state. : 
““On the whole, therefore, while again repeating that the controversy now has only an 
academic importance, the weight of evidence favors the view that spirochetes as a group 
are structurally (ectoplasmic) more complex and more plastic and variable in form than 
bacteria, while functionally they have a more complicated life history. On the other 
hand, their structures (endoplasmic especially) are much less complex than in protozoa, 
and their life history, so far as it is known, more simple than that of the known protozoa. 
Until further observations on the life histories of different species are made we are 
justified in doing no more than to place the spirochetes as an intermediate group 
between the bacteria and the protozoa, but leaning more toward the latter, and in this 
sense they are included under the name spirocheetida in our classification.” 
A. TYPE GENUS SPIROCHAETA 
With undulating membrane; without flagella. 
Spirocheta plicatilis. Ehrenberg, 1838. Free living. Length up to 200#. 
Sp. balbianit. Certes, 1882. In oysters, clams, etc. Length up to 150#. 
Sp. anodontac. Keysselitz, 1906. Mussel (anodon). Length up to 604. 
Sp. vincenti. Blanchard, 1906. Human ulcers. 
Sp. pyogenes. Mezincescu, 1904. Tuberculous cattle. 
Sp. refrigens. Schaudinn, 1905. Human syphilitic lesions (external). 
Sp. pseudopallida. Kiolemenoglou and von Cube. Ulcerating carcinoma. 
Sp. eberthi. Kent, 1880. Bird intestine. 
Sp. gigantea. Warming, 1874. 
Sp. buccalis. Steinberg, 1862. Probably same as dentium. Same habitat. 
B. GENUS TREPONEMA 
Without undulating membrane; with flagella. 
Treponema pallidum. Schaudinn, 1905. In human and ape syphilitic lesions. 
Tr. pertenuis. Castellani, 1905. In lesions of frambesia or yaws. 
Tr. ansertnum. Sacharoff, 1890. Blood of geese. 
Tr. gallinarum. March and Salimbeni, 1903. Blood of chickens. 
Tr. theileri. Laver and Vallée, 1904. Blood of cattle. 
Tr. muris. Wenyon (Tr. Laverani, Breinl and Kinghorn). Blood of mice. 
C. UNDETERMINED FORMS REFERRED TO GENERA SPIROCHAETA AND SPIRILLUM 
Spirocheta dentium. Koch, 1877. Human mouth and teeth. 
Sp. vaccine. Bonhof, 1905. Pustules of calf. 
Sp. recurrentis (Sp. obermeieri). Lebert, 1874. Cause of relapsing fever. 
Sp. duttoni. Novy and Knapp, 1906. Cause of tick fever in man. 
Sp. microgyrata. Lowenthal, 1906. Ulcerating human carcinoma. 
Sp. microgyrata. Léw. var. Gaylordi. In non-ulcerating mouse tumors. 
Sp. of dysentery. Le Dantec. 
Sp. ovis. Novy and Knapp. Blood of sheep. 
