Apr. 19,1924 
Bacterial Leaf spot of Delphinium 
267 
Table I .—Sources of nitrogen 
1 day old 
4 days old 
10 days old 
20 days old 
Peptone. 
Very weak cloud- 
Good clouding, heavy 
pellicle. 
Weak clouding, deli¬ 
cate pellicle. 
_do.. 
Same as 4 days, some 
precipitate. 
Moderate clouding, 
good pellicle. 
Weak clouding, deli¬ 
cate pellicle. 
Weak clouding, no pel¬ 
licle. 
.do. 
No further 
Asparagin + dex¬ 
trose. 
Asparagifi. 
growth. 
Do. 
. 
.do. 
Do. 
Ammonium citrate. 
.do. 
Weak clouding, no pel¬ 
licle. 
.do. 
Do. 
Ammonium succi¬ 
nate. 
Ammonium tar- 
.do. 
Do. 
No clouding. 
No growth. 
Very weak clouding.... 
Do. 
trate. 
Litmus sugar agars. —Litmus agar containing 1 per cent peptone and 1 per cent 
of saccharose, maltose, lactose, dextrose, galactose, levulose, 1. arabinose, glycerin 
or mannit was used for stroke cultures. The litmus is reddened decidedly on 
the second day and is red throughout in 6 days in the presence of dextrose, levu¬ 
lose, 1. arabinose or -galactose. Saccharose causes no color change except some¬ 
times a very feeble reddening after 2 to 3 weeks. Cultures with maltose, lactose, 
glycerin and mannit become decidedly blue, beginning on the second day. 
When the same carbohydrates are added to beef infusion peptone litmus 
agar the organism produces a blue reaction with all of them. 
Fermentation tubes. —In fermentation tubes containing 1 per cent peptone 
water and 1 per cent of saccharose, lactose, maltose, dextrose, galactose, glycerin 
or mannit, there is no growth in the closed end and no gas. In dextrose and 
galactose the reaction is acid to litmus while the others are alkaline to litmus. 
They were tested after 1 week, 2 weeks, and 4 weeks. Saccharose gives a neu¬ 
tral or slightly acid reaction. 
Blood serum. —Only a very moderate growth takes place on Loeffler’s blood 
serum and there is no liquefaction. 
Toleration op sodium chlorid. —The organism grows promptly and well in 
1 per cent NaCl in +10 or +12 beef bouillon and fairly well in 2 per cent, 
weakly in 3 per cent, and some isolations make very weak growth in presence of 
4 per cent NaCl. 
Optimum P h in beep bullion. —The best growth was made in +16 (P H 6.7) to 
+12 (P H 7.1). There was gradual but finally very good clouding in +25 
(P H 5.6), but none in +30 (P H 5'2). Moderate clouding occurs in 0 (P H 8.2), 
weak clouding in —2 (Ph 8.4) and in —4 (Ph 8.6), but none in —9 (Ph 9.2). 
Toleration op organic acids. —Tests made with citric, malic, and tartaric 
acids are summarized in Table II. It was found that the Ph value is the con¬ 
trolling element here, the organism being able to grow in the same Ph of all acids 
while varying in its tolerance of the different acids judged by their Fuller's scale 
values. 
Ammonia production. —There is strong ammonia production. Cultures in 
beef bouillon 2 to 17 days old were tested by suspending over them strips of filter 
paper wet with Nessler's solution. Browning of the paper began immediately 
and became intense on heating the cultures in a water bath. 
Hydrogen sulphid production. —No hydrogen sulphid is given off from 
bouillon, Uschinsky's solution, Fermi's solution, or potato cultures. Tests were 
made by suspending filter paper wet with lead acetate water in the tubes. No 
discoloration of the paper occurred. 
