Ward. — A Violet Bacillus from the Thames . 69 
Temperature. 
Liquefaction. 
Rapidity of 
growth. 
Pigment. 
Reactions to 
light. 
Pathogenicity. 
The Bacilli are still alive after several days at 35 0 C., but no 
growth is maintained; growth occurs at 5 0 C. The best 
temperature seems to be near 20° C. Old cultures withstand 
50° to 6o° C. for some hours, though no true spores are known. 
Liquefies the gelatine, but only slowly after the upper parts are 
fluid, and the deeper parts may be solid months afterwards. 
Slow. In many cases colonies are found only 10 or 12 mm. in 
diameter six months after making a plate, the gelatine around 
having dried up ; they are usually about half that diameter when 
the gelatine liquefies, and they float in it. 
Deep violet. Not in the cells, and does not diffuse into the 
solid media, except perhaps a little on potatoes. Insoluble in 
water ; very soluble in alcohol, and looks like gentian-violet ; very 
stable except in sunlight. Turns bluish green on adding NaHO, 
the original colour almost restored by excess of acid. Acetic acid 
to original solution makes it paler. Absorbs yellow-orange to 
green-blue. 
Easily killed on exposure to direct sunlight. At moderately 
high temperatures the Bacilli, quiescent in darkness, move actively 
when illuminated. 
Prof. Kanthack finds it not pathogenic for guinea-pigs. I have 
to thank Prof. Kanthack for examining pathologically a large 
number of these Thames Schizomycetes. 
Interesting and important results were obtained on reviving 
No. 2 from an agar-tube which had remained untouched from 
August 15 to June 9, i. e. ten months. 
The plate-colonies at 20-22° C. eventually came up white 
and quite normal, except that they were more tough and 
membranous than expected, and the needle lifted each colony 
whole from its liquefying disc. At first they were pure white, as 
usual ; but in ten days the purple colour appeared in the middle 
or at the margins, and rapidly spread. Until the purple hue 
appeared, I was inclined to suspect the plates were not pure, 
and that the colonies were those of a capsuled Bacillus. 
The tube-cultures were also normal, and the purple mem- 
branes of the broth- and milk-cultures appeared on the tenth 
to eleventh days at 20-25° C., so that no doubt need exist as 
to the species. At the same time it should be noted that 
some of the plate-colonies remained white or yellowish-white 
to the end, and that great variations were exhibited as to the 
degree of liquefaction and coherence of the colonies. I was 
