CE 
~- _ SSE ce ee) 
a _ — 
1899 | PRODUCTION OF FLUORESCENT PIGMENT 21 
5. B. vir1IpANS.— A microorganism was first described under this name 
by Symmers.”? Zimmermann ® also described a form found in polluted water 
which he pronounces wholly identical with a culture of B. viridans (Sym- 
mers), obtained from Kral. My own culture bearing this name was sent me 
from Kral’s collection. 
The bacilli vary considerably in dimensions when grown on different 
media. They are short and quite slender in broth cultures, longer and 
plumper on potato. On the latter medium they average about 0.8-o.gu by 
2.5—3u. They occur usually singly or in pairs when grown in broth, and are 
non-motile. They stain with the ordinary aniline dyes, but not so readily as 
with carbol-fuchsin or Léffler’s methylene blue. They do not retain the stain 
by Gram’s method. Gelatin is liquefied very rapidly, the growth in a stab- 
culture occurring at the upper part of the inoculation line and giving rise to 
a saucer-shaped depression. The growth in agar streak-culture is gray, thin, 
fairly spreading and with serrated edges. The medium is speedily colored a 
fine blue-green which in seven days has changed to a dark Nile-green. The 
growth on potato is luxuriant, at first dry and of a tan-color, but later becom- 
ing dark and slimy. Milk iscurdled with acid reaction, and the whey assumes 
a decided green color. No indol is formed, and nitrate is not reduced. In 
the fermentation tube no gas is produced in glucose bouillon but the medium 
becomes strongly acid. At 37-5° C. a very scanty growth occurs, but no pig- 
ment is produced. 
Zimmermann? classifies this organism as one that produces green, but not 
fluorescent pigment. I have not been able to remark the existence of any 
such difference between my culture of 2. viridans and the other organisms 
I have studied ; fluorescence is manifest in all. 
- ). FL. LIQUEFACIENS.— A germ isolated by me from the water of 
Lake Michigan. I have given it the above name, since the culture agrees 
with the description of the species by Kruse.’° The chief differences between 
this culture and that of B. viridans are the following: (a) no growth at all 
occurs at 37.5°C.; (6) growth in gelatin stab-cultures is more rapid than that 
of B. viridans under the same conditions, but pigment is less abundantly 
produced ; (c) the bacilli are actively motile; (¢@) growth on potato is from 
the outset moist and slimy; (e) nitrate is readily reduced to nitrite. 
It is evident from these descriptions that the existing differ- 
ences between some of the cultures I have employed are hardly 
to be regarded as specific, whatever may have been the case with 
the type microorganisms when first isolated. I shall for conve- 
’British Medical Journal 2: 1252. 1891; cf. also Brit. Med. Journ. 1: 113. 1893. 
8 Op. cit. 2: 22. ‘t. 
*° Fliigge’s Die Mikroorganismen, doc. cit. 
