DESCRIPTION OF SPECIES. 



567 



to 12 p long, 1-5 to 2-6 p thick. 

 They are colourless, but the con- 

 tents include strongly refractive 

 sulphur granules. Also spirals 6 to 

 7'5 \i in height, which are actively 

 motile. 



They were found in brackish 

 water. 



Spirillum rubrum (Esmarck). 

 Curved rods, spirilla and spiro- 

 chetae. They are actively motile. 



The growth on artificial media is 

 extremely slow. 



Inoculated in the depth of gela- 

 tine they grow along the track of 

 the needle, forming a filament of a 

 wine-red colour, without causing 

 liquefaction ; and on the free sur- 

 face the growth is colourless. 



In broth long spirillar threads 

 are formed. 



They were isolated from the 

 putrid tissues of a mouse. 



Spirillum rufum (Perty). 

 Filaments from 8 to 16 /z in length, 

 with 1^ to 4 screw curves ; non- 

 segmented ; chiefly motile ; tinged 

 with red. 



They form rose or dark red spots 

 on the sides of wells. 



Spirillum sanguineum (Cohn). 

 Threads 3 \L and more in thick- 

 ness, with 2 to 2 spirals, each 9 to 

 12 /u. high. The ends are provided 

 with flagella. Their colour is due 

 to the presence of reddish granules 

 contained in the cells. 



They were observed in brackish 

 water containing putrefying sub- 

 stances. (Vide Beggiatoa roseo- 

 persicina. ) 



Spirillum saprophiles. (I.) 

 Curved rods with pointed ends, -6 /L* 

 in width, 3 \JL in length ; spirilla, 

 spirilliform filaments, and involu- 

 tion forms. 



Colonies yellowish or greenish- 

 yellow. 



Inoculated in the depth of gela- 

 tine a white growth forms in the 

 track of the needle, later becoming 

 yellowish ; and on the free surface 

 there is a white growth, and 

 beyond this a transparent film 

 spreads over the jelly. 



On agar the growthi s creamy, 

 and the jelly clouded beneath it. 



On potato the growth is slimy 

 and yellowish or dark-brown in 

 colour. 



They were obtained from sewage 



FIG. 226. COMMA-BACILLI IN WATER 



CONTAMINATED WITH SEWAGE. 



mud and decomposing hay infu- 

 sion. 



(II.) Curved rods about 2 p in 

 length, with blunt ends and in pairs. 

 Extremely motile. 



Colonies circular and yellowish- 

 brown. 



Inoculated in the depth of gela- 

 tine a white growth develops in 

 the track of the needle, and later 

 becomes yellowish-red ; on the free 

 surface a white patch forms, sur- 

 rounded by a transparent film. 



In the depth of agar there is no 

 growth in the track of the needle, 

 but a yellowish-white patch on 

 the free surface adherent to the 



jelly. 



On potato the growth is also 

 adherent, and in appearance shining 

 and brownish-green. 



They were isolated from decom- 

 posing hay infusion. 



(III.) Curved rods, spirilla, and 

 spirilliform filaments, and involu- 

 tion forms. 



Colonies are circular, granular, 

 and with irregular margin ; yellow 

 in the centre, and white at the 

 periphery. 



Inoculated in the depth of gela- 

 tine a white growth develops in 

 the track of the needle, and on the 

 surface, without producing lique- 

 faction. 



On the surface of agar the growth 

 is white. 



On potato the growth is distinctly 

 brown. 



