FEBRUARY 9, 1912] 
Group O.—Differentiated primarily by slow, 
scanty, colorless or white growth. Morphologically 
smaller than organisms of group B; thick, curved, 
with solid, barred and wedge forms. Ferments 
dextrose, always; saccharose usually, maltose and 
glycerin in 50 per cent. of cultures. The xerosis 
bacillus apparently belongs to this group. 
CONCLUSIONS 
1. The division of diphtheria bacilli into virulent 
and non-virulent varieties is justified by differ- 
ences in morphology and degree of fermentative 
powers, and by the absence of intermediate grades 
of virulence, as shown by animal inoculations. 
2. The common ‘‘diphtheroid’’ organisms found 
in the human body fall into three sub-groups. 
3. B. Hoffmann’s has no biological relationship 
either to the diphtheria bacillus or to the diph- 
theroids. 
A Biometric Investigation of Certain Non-spore- 
forming Intestinal Bacilu: EuGENE C. Howe. 
Six hundred and thirty strains of intestinal 
bacilli were collected from stools of twenty-one 
individuals—mostly healthy men. These were sub- 
jected to the following quantitative tests: (1) 
Acid and gas formation in dextrose, lactose, sac- 
charose, raffinose, levulose, mannite and dulcite. 
(2) Acid production in milk. (3) Digestion of 
starch. (4) Production of indol from peptone. 
(5) Reduction of nitrates. (6) Gelatin liquefac- 
tion. (7) Morphology. (8) Motility. 
The resulting data were analyzed statistically 
with the following conclusions to date relative to 
the non-gelatin liquefiers (540 strains): 
1. Confirmation of the accepted view that mo- 
tility has not systematic significance within the 
group ‘‘B coli and closely related organisms.’’ 
2. Lack of classificatory value of amount of gas 
produced and ‘‘gas ratio.’’ 
3. Acid formation, a sounder criterion than pro- 
duction of gas. 
4, Mannite, dulcite and starch of little value in 
classification of this group, in connection with the 
other tests used. There is no correlation between 
the first three and the latter. 
5. Indol, ammonia, and nitrite formation but 
slightly correlated with the general robustness of 
the organism and of little significance in classifica- 
tion within this group. 
6. Dextrose, lactose, saccharose and raffinose 
constitute a natural metabolic gradient. Fermen- 
tation of any member of the series implies fer- 
mentation of members lower in the series. 
SCIENCE 
225 
7. On this basis there are two main groups of 
dextrose fermenting, gelatin-minus, mnon-spore- 
forming, intestinal bacilli and four sub-groups. 
I. (58 ee + Lact. + Sac. + Raf. + 1 (53 2) 
y Dex. + Lact. + Sac. + Raf. — 2 (5 #) 
Dex. + Lact. + Sac. + Raf. — 3 (41 #) 
He (e3 Ae + Lact. — Sac. — Raf. — 4 (17) 
The Green Fluorescent Bacteria of Maple Sap: 
H. A. Epson and C. W. CARPENTER. 
Green fluorescent bacteria are the most impor- 
tant agents in the deterioration of maple sap. 
These microorganisms feed upon the traces of 
protein present in the sap, but have little, if any, 
action upon the sugar. The sap becomes cloudy 
with more or less green color and produces an 
inferior quality of syrup and sugar. 
Forty-two strains of this group of bacteria 
which were isolated from maple sap, together with 
five cultures of known species from Kral and one 
from Novy, were studied. The latter were: B. 
fluorescens albus, B. fluorescens liquefaciens, B. 
fluorescens longus, B. fluorescens mesentericus, B. 
fluorescens tenwis and B. fluorescens putidis. The 
chief differences observed in the entire series of 
cultures were in respect to the following charac- 
ters: nitrate reduction; growth on synthetic 
media; gelatin liquefaction and casein digestion 
in milk; hydrogen sulphide production; tempera- 
ture relations. 
Thirty-three strains of the fluorescent sap bac- 
teria agree closely with B. fluorescens liquefaciens ; 
two strains resemble B. fluorescens mesentericus 
and seven strains are similar to B. fluorescens 
tenuis. 
Bacterial Variation Due to Acidity and Flow in 
the Youghiogheny River at McKeesport, Penn- 
sylvania: EB. C. TRAX. 
The germicidal action of drainage from coal 
mines, containing as it does free sulphuric acid 
and iron in solution, is indicated by its com- 
position. 
Experiments made by the Department of Health 
of Pennsylvania lead to the conclusion that ‘‘Mine 
water will prevent the growth of typhoid bacilli 
after the lapse of one hour, and will markedly 
limit the growth of colon bacilli so that they die 
off progressively and can not be cultivated after 
24 hours.’’ 
The acidity of the water in the Youghiogheny 
River is caused by the acid mine drainage, an 
immense quantity of which is discharged into the 
river and its tributaries. The reaction of the 
