402 MICEO-ORGANISMS IN WATER 



BACILLUS CHOLEEOIDES ^ 



LIQUEFIES GELATINE 



Authority. — Orlowski. See Bujwid's paper, p. 121. 



Where Found. — In well-water in the neighbourhood of which many cholera 

 cases had occurred. 



Microscopic Appearance.— This organism- resembles the Comma spirilJ/um 

 even more closely than the above; it grows, however, more anaerobically, and 

 forms a much deeper liquefying funnel. 



Bemarks. — Finkelnburg (' Zur Frage der Variabilitat der Cholerabacillen,' Cen- 

 iralblatt f. Bakteriologie, vol. xiii., 1893, p. 113) states that in consequence of its 

 long residence in culture media the original Comma bacillus has undergone a gradual 

 degeneration of its biological energies. It is quite possible, therefore, that the above 

 spirilla may be true cholera organisms, although deviating slightly from Koch's 

 original spirillum. 



(EINE NEUE VIBRIONENAET) 



LIQUEFIES GELATINE 



Authority. — Weibel, 'Ueber eine neue im Brunnenwasser gef undene Vibrio- 

 nenart,' Centralblatt filr Bakteriologie, vol. xiii., 1893, p. 117. 



Where Found. — In a weU water. 



Microscopic Appearance. — Eesembles the Comma spirillum, also the Vibrio 

 saprophiles a (see p. 404), but on the whole it is rather larger than the former. 

 The most characteristic comma-shaped forms are obtained in broth. 



Cultures. — 



Gelatine Plates. — Appears at first in the form of dull white dots, which 

 under a low power are translucent light-brown mostly circular discs, with a 

 smooth rim and homogeneous structure. It liquefies the gelatine much more 

 rapidly than the Cmnma spirillum, and under a low power the centre is dark 

 and broken up, surrounded by a light evenly granular outer zone, which is 

 followed by a rather darker zone consisting of closely packed and very fine 

 radial lines. In consequence of the varying degrees of lightness of this border 

 an impression is conveyed of a delicate folding or crinkling of the periphery. 

 Many colonies before liquefaction begins form dull white flat expansions, which 

 under a low power are irregularly circular, pale yellowish in the centre, and 

 dull grey or colourless towards the edge. In these the liquefaction begins m 

 the centre of the colony, the latter forming a circular yellowish depression. 

 The rate of liquefaction is very variable, appearing to depend upon the free 

 access of air, being less rapid in the closed Esmarch tubes than on ordinary 

 plates. 



Gelatine Tubes. — Develops all along the needle's path in the depth, forming 

 a flat dish-shaped concavity on the surface ; at the bottom of the liquid 

 gelatine a crumbly white deposit forms, whilst the liquid above is quite 

 clear. 



Agar-agab.— Forms a grey expansion on the surface; a growth is also visible 

 in the depth. It grows more rapidly at 37° C. 



Potatoes.— No development. 



Broth.— Renders it slightly turbid, forming a deposit. It, as a rule, forms 

 no pellicle, but a delicate circular growth which clings to the sides of the tube, 

 and which is easily disengaged by shaking, and sinks often without breaking 

 to the bottom of the tube. At 37° C. the development is more rapid and 

 luxuriant. 



Bemarks.— When exposed to 55° C. for thirty minutes it is destroyed. 



