260 THE HAEMOFLAGELLATES 



above. In addition, there is the most important point that some species 

 of Piroplasma are stated to show, at certain times, the same characteristic 

 nuclear dimorphism. Schaudinn was the first to notice this, in the case of 

 P. canis ; and he was confirmed by Kossel and Weber. Since then additional 

 observations to the same effect are recorded by other workers (e.g. Lithe) 

 for various species. This being so, the Piroplasmata also are most 

 probably to be derived from Flagellate forms. 1 



-(B) A word or two, lastly, with reference to the supposed connection 

 of the Xpirochadae with the Trypanosomes. Besides the instance of 

 Trypanosoma (Spirochaeta) demanni, Schaudinn, in his great memoir (I.e.), 

 was inclined to consider that other Spirochactae (e.g. S. obermeieri of 

 relapsing fever) were also only phases in the life-cycle of other Haemo- 

 Hagellates. Subsequently, however, as a consequence of his investigations 

 on Spirochaeta plicatilis, the type-species, and other forms, he relinquished 

 this view, finding that the latter were of a totally different nature, and 

 should rather be placed with the Bacteria. Much has since been written 

 with regard to the nature and affinities of the various Spirochaetae. We 

 do not propose to go into the general question here, as the preponderance 

 of opinion is decidedly against these organisms belonging to the Protozoa. 

 It is only necessary to mention one or two forms which have been 

 definitely referred to the Trypanosomes. Certes, in 1882, described a 

 parasite from the digestive tube, including the crystalline style, of oysters, 

 which he named Tnjpanosoma balbianii. A few years ago Laveran and 

 Mesuil (99) re-examined this organism, and came to the conclusion that 

 it was not a Trypanosorne but a Bacterium, allied to Spirochaeta. Other 

 workers who have recently observed this form also agree that its structure 

 shows none of the essential features of a Trypanosome, but, on the contrary, 

 greatly resembles that of a true Spirochaete. Perrin, it may be noted, 

 has endeavoured (100) to connect it with Schaudinn's bipolar " Ur- 

 haemoflagellate." This idea has received no support, and indeed Perrin's 

 whole paper is most unconvincing. Another, much more important 

 example is that of the remarkable spirochaetiform parasite first described 

 by Schaudinn and Hoffmann (103) in cases of syphilis, and which is 

 now considered to be most likely the cause of that disease. Sehaudhm 

 found (102) that this organism differs in many ways from an ordinary 

 Spirochaeta, and placed it in a new genus Treponema as T. pallidum. 

 In a recent memoir (101), Krzyszfalowicz and Siedlecki have given a 

 detailed account of this organism, and state that they have observed 

 distinct trypaniform stages in its life-cycle. For this reason they con- 

 sider it to be allied to the Trypanosomes and place it actually in the 

 genus Trypanosoma, as T. luis. This view lacks, as yet, corroboration, 

 and so here, as in the case of Schaudinn's research, the question must 



1 Since this was written we are able to add that confirmation of this view is forth- 

 coming. In a most important note, Miyajima (Philipp. J. Sci. ser. B, ii. 1907, p. 

 83) describes the development of Flagellate-phases in cultures of a Piroplasma 

 (cf. parvum) of cattle in Japan. In seventy-two hours, forms with well-developed 

 undulating-membrane were numerous. The author seems to have carefully guarded 

 against the possibility of this highly-interesting occurrence being due to undetected 

 Trypanosomes present in the blood. 



