322 H. M. WOODCOCK. 



Further careful investigation of all (including, e. g. '^ S." 

 obermeieri and " S." anserina) is necessary, with a view 

 to their correct sorting and classification. 



In conclusion, the occurrence of Spironema (Trypano- 

 soma) pallidum in syphilis is extremely suggestive when 

 the very similar biology of Trypanosoma equiperdum 

 and its causal relation to Dourine (horse syphilis) are borne 

 in mind (cf. above, p. 176). The former parasite has un- 

 doubtedly been evolved along similar lines to the latter. 

 Probably, indeed, the two are not distantly connected, 

 although Spironema is apparently more modified, and 

 almost certainly now restricted to the Vertebrate host. 



BiBLIOGEAPHY. 



[This list is intended to be a guide to the principal papers 

 in connection with the zoological and biological study of the 

 parasites published up to the end of January, 1906.] 



A. Relating to the Try pauosomes. 



1. Bettencoort and Tranpa, C. — " Sur un Tiypanosome du blaireau 



(Meles taxus, Schreib.)," 'C 11. Soc. Biol.,' 59, p. 305, 1905. 

 2. "Trypauosome de la cliauve-souris," t. c, p. 306, 1905. 



3. Billet, A. — " Culture d'un Trypanosome de la grenouille chez une 



Hirudinee ; relation ontogeuique possible de ce Trypanosome avec une 

 Hemogregarine," ' C. B. Ac. Sci.,' 139, p. 574, 1904. 



4. "Sur le Trypanosoma inopinatum de la grenouille verte 



d'Algerie et sa relation possible avec les Drepanidium," 'C. R. 

 Soc. Biol.,' 57, p. 161, 16 figs., 1904. 



5. Bosc, F. J. — " Recherclies sur la structure et I'appareil nucleaire des 



Trypanosomes (a propos d'un Trypanosome observe chez le lapin)," 

 ♦ Arch. Protistenk.,' 5, p. 40, 68 figs., 1904. 



6. BuADi'ORD, J. R.,and Plimmek, U. G. — "The Trypanosoma brucii, 



the organism found in Nagana or the Tsetse- fly disease," ' Q,. J. Micr. 

 Sci.,' 45, p. 449, 2 pis., 1902. [This species was originally named and 

 described in T. R. Soc.,' 65, p. 274, 1899.] 



7. Bruce, D. — "Note on the discovery of a new Trypanosoma," 



' Lancet,' 1902, i, p. 664, and ' Nature,' 65, p. 454, 1902. 



