A Violet Bacillus from the Thames. 
BY 
H. MARSHALL WARD, Sc.D., F.R.S. 
Professor of Botany in the University of Cambridge. 
With Plate VI. 
NE of the most interesting forms of Schizomycete I have 
isolated from the Thames 1 is a bacillar or filamentous 
one observed more especially in the winter, though probably 
present also in the summer with altered characters. 
It is remarkable for producing in vigorous cultures a mag- 
nificent violet pigment of a peculiarly pure hue ; in fact 
almost exactly the colour of dark blue violets, or of a strong 
solution of gentian-violet. 
This species grows well and is easily cultivated at all 
temperatures from about io°C. to 25 0 C., on all the ordinary 
solid media, and in milk and broth, though difficulties are 
occasionally met with in potato-cultures. Specimens in 
gelatine and broth-drops grow out as long filaments, often 
50 to 60 jut and longer, which move with an oscillating and 
sinuous motion, or progress slowly across the field with 
similar movements. These filaments are obviously segmented, 
1 See Proc. Roy. Soc., Vol. lxi, 1897, p. 415. The form here described is that 
constituting the type of Group II on p. 417. 
[Annals of Botany, Vol. XII. No. XLV. March, 1898.] 
