SPIROCHHTA BALBIANII AND SPIROCHHTA ANODONTA. 65 
(cf. p. 7 of this memoir). He describes very briefly the 
movements of S. balbianii, but does not account for them. 
His fixation was strong formalin, which I have not found to 
be so useful as osmic vapour or even methyl alcohol. No 
myoneme fibrille are figured in Swellengrebel’s paper. Al- 
though allowing that the spiral filament of chromatin divides 
in a longitudinal plane, yet the organism is said to divide 
transversely. This is probably explained on reference to my 
fig. 19 (Plate 3) and p. 46, paragraph 3. 
Moreover, it is interesting to look up the older writers on 
Bacteria, such as Zopf (86), for their views on Spirochetes. 
Zopf, although believing in pleomorphism and in the absence 
of a nucleus in Bacteria, yet notes that bipartition may take 
place in two or even three directions, though usually only in 
one (cf. this memoir, p. 45). Regarding locomotion he notes 
that cilia may be present in some forms (though apparently 
not in Spirochetes) as eversible projections through the 
envelope, and that, in addition, there is an oscillatory move- 
ment. 
In conclusion, I hope I may be permitted to state that the 
observations recorded in this memoir, and the interpretations 
of them herein set forth, are the result of protracted and 
earnest endeavours to grapple with probably the most difficult 
eroup in the whole range of Protozoology, a group of the 
utmost morphological and economic importance, all previous 
accounts of which are most conflicting or only deal with minor 
points. I trust then, that this memoir of mine may be thus 
considered and lead to further investigations of organisms 
like S. obermeieri and S. gallinarum of relapsing fevers, 
along the lines and from the important points of view herein 
suggested. . 
UNIVERSITY CoLLEGE, Lonpon ; 
October, 1907. 
The following list of References to Literature is not 
claimed to be a complete one on Spirochztes—but only a list 
of many of the more important memoirs thereon. Further 
VOL. 52, PART 1.—NEW SERIES. 5 
