no 
Spiral Organism in the Cat 
the spirochaetes often exhibit granules and vacuoles. The granules stain 
darkly with the basic dye and are undoubtedly chromidia; they are inconstant 
in number (see PI. VII, fig. 5). Vacuoles are not nearly so common, and may be 
artefacts resulting from overheating. Very broad forms of the spirochaete 
are probably also due to this cause. 
Behaviour of living spirochaetes. If a little of the gastric mucosa is scraped 
off and transferred to a slide, the spirochaetes may be easily studied without 
the use of the dark ground illumination. They are highly retractile and 
quickly catch the eye, by the distinctness and regularity of their spirals. One 
or two more highly retractile spots may be seen at one or both ends of some 
of the organisms, but, otherwise, they appear homogeneous and structureless. 
When not in progression, the spirochaetes are seen in various attitudes, 
either straight, curved like a semicircle, or more completely, like a loop, and 
show one or other of the following movements which may be very active: 
(1) An intermittent corkscrew-like motion of their spirals, sometimes in 
one direction, and sometimes in the reverse direction. Occasionally, one end 
appears to turn more slowly than the other. (2) Large spiral movements, 
superadded to the smaller movements. (3) A circular sweeping movement 
of one extremity. (4) Lateral oscillation of the whole organism. (5) A rotary 
disturbance of the fluid medium at one end of the organism, although the 
visible extremity of the spirochaete is not in motion. This seems to suggest 
the presence of a fine terminal filament (flagellum). 
The behaviour of some spirochaetes in the proximity of cells is interesting. 
They ram the cell and spiral or corkscrew furiously, occasionally giving large 
circular sweeps with their* free ends. Suddenly they disengage themselves, 
turn a “somersault” and repeat the performance with the former free end. 
No spirochaetes, however, have been actually observed to penetrate a cell 
by this means. The method of progression is difficult to analyse, but it 
appears to consist of a combination of corkscrew and lateral movements. 
CULTIVATION. 
All attempts at cultivation have hitherto failed. Deep agar, cooked-meat, 
and gastric digests, with or without pepsin, HC1 or serum, have been used 
with no success. Partial anaerobiosis was maintained in all cases, except 
when agar was employed, by means of a supernatant layer of liquid paraffin. 
The only result obtained, worthy of note, was that the spirochaetes may 
survive at least four days in an acid medium (0-02 per cent. HC1). 
CONCLUSIONS. 
From the incomplete data accumulated, it is not possible to classify the 
organism just described, but sufficient is known to regard it as a new species 
of the Spirochaetoideae. Morphologically, it resembles both the genus Spiro- 
nema and the genus Treponema (as defined by Noguchi, 1918). It reacts to 
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