478 THE SPIROCHETES 



but the filamentous appendages are demonstrable only by special technique. In fresh- 

 ly excised materials, immediately fixed, the pallidum shows irregular spirals, owing 

 to the fact that the organisms were in active movement when suddenly killed by 

 fixation. 



Treponema pallidum and T. pertenue were obtained on artificial media in 1911-12. 

 The methods are described in another section (pp. 46^-71). 



Treponema cuniculi {Figs, gy-ioo). — The occurrence of a spiral organism indis- 

 tinguishable from T. pallidum in a spontaneous venereal disease of rabbits was de- 

 scribed by Ross' and by Bayon^ in 191 2 and 1913. The condition was subsequently 

 studied by a number of workers. The names proposed for the organism were T. 

 paraluis cuniculi (Jacobsthal)^ and T. pallidum var. cuniculi (Klarenbeek).^ The 

 latter is the valid designation, according to the International Code of Nomenclature, 

 but it seems justifiable to make cuniculi a species rather than a subspecies. ^ 



T. cunicidi is an organism of great importance to the experimental worker be- 

 cause of the widespread employment of the rabbit in the study of syphilis. Although 

 the organism cannot be differentiated from T. pallidum, the spontaneous lesion of 

 the rabbit, which consists of slightly elevated, scaly areas, is not readily confused 

 with the marked induration induced by inoculation of the syphilis organism.'' More- 

 over, the lymph nodes are seldom palpable after inoculation of T. cunicidi, nor are 

 chancres, orchitis, or keratitis readily induced by the organism. The histological 

 changes in the affected tissues resemble those of a condyloma. The Wassermann re- 

 action is negative in rabbits infected with T. cunicidi, and positive in those having 

 lesions induced by T. pallidum or T. pertenue. 



T. cuniculi, as well as T. pertenue and T. pallidum, is easily destroyed by arseno- 

 benzol, and healing of the lesions follows treatment with the drug. 



Treponema {?) argentinesis. — This organism was described by Kuhn and Steiner" 

 in 1917, having been found by them in the liver tissue of guinea pigs and rabbits in- 

 fected with blood or spinal fluid of multiple sclerosis patients. It is pathogenic for 

 rabbits and guinea pigs, inducing paralysis, emaciation, and death. The presence of 

 the organism in human and experimental tissue was confirmed by Siemerling,'^ 

 Buscher,' Speer,'" Marinesco," and Kalberlah'^ as well as by Kuhn and Steiner."'' 



In the Levaditi-stained preparations kindly sent me by Professor Steiner, the 



1 Ross, E. H.: Brit. M. J., 2, 1651. 1912. 



2 Bayon, H.: ibid., p. 1159. 1913. 



3 Jacobsthal, E.: Dermat. Wchnschr., 71, 569. 1920. 



4 Klarenbeek, A.: Ceniralbl.f. BakierioL, Orig., 87, 203. 1921. 



5 1 am indebted to Dr. Stiles for an opinion with regard to this name. 



^Noguchi, H.: /. Expcr. Med., 35, 391. 1922. 



7 Kuhn, P., and Steiner, G.: Med. Klin., 13, 1007. 1917. 



* Siemerling, E.: Berl. klin. Wchnschr., 55, 273. 1918. 



'Biischer, J.: Arch. f. Psychial., 62, 426. 1920. 



"Speer, E.: Munchen. med. Wchnschr., 68, 425. 1921. 



" Marinesco, G. : Rev. ncnrol., 26, 481. 1919. 



" Kalberlah, P.: Deutsche med. Wchnschr., 47, 102. 1921. 



'3 Kuhn, r., and Steiner, G.: Ztschr.f. Hyg. it. Infeklionskrankh., 90, 417. 1920. 



