40 H. B. FANTHAM. 
an attempt at loosening the spiral or coil of the helix during 
a period of activity such as occurs at division. It has 
already been mentioned that a slightly loosened condition of 
the spiral is probably to be correlated with a period of activity. 
The resulting chromatin masses, after the division of the 
dumb-bell shaped rodlets, do not seem to be arranged always 
exactly opposite each other along the periphery of the body, 
owing to the slight loosening of the spiral just mentioned, 
and to the general torsion of the body. In the daughter 
forms thus produced, the chromatin masses and the remains 
of their attached threads join up (text-fig. 9, e.), and so form 
a very slightly coiled spiral or even a longitudinal rod, such 
as one sees in long attenuate forms of the parasite, which 
are probably young forms, though some protistologists would 
consider these to be male forms. But the condition of the 
nucleus as a central longitudinal rod may result from over- 
staining—which is often necessary for showing the details of 
the membrane—when the true spiral nature is obscured, and 
this must be borne in mind in interpreting the condition of 
the nucleus of these Spirocheetes. 
The above statements represent the views I have formed, 
as a result of observation, on the nucleus of S. balbianii. 
Tam sorry I do not agree in all details with Perrin (9), but I 
am unable to correlate some of his complicated phases with 
the appearances of the actual specimens. However, I have 
the greatest admiration for Perrin’s work, which was largely 
that of a pioneer in elucidating the nuclear details of 
S. balbianii. 
Swellengrebel (10), in his recent note on Spirillum 
giganteum, mentions the arching or vaulting of the 
chromatin filament (... “le filament former une anse”’), 
and thus supports the view of the helicoid nature of the 
spiral, for he states that the same nuclear structure obtains 
in 8S. balbianii. This disposes of the ideas of the earlier 
observers, especially Lustrac (6), who considered the centre 
of the organism to be alveolated, and overlooked altogether 
the presence of chromatin, but that was only to be expected 
