BACTERIA OF PLANT DISEASES. 573 
Jecting part of the cylinder was covered with a copious, wet-shining growth. 
-\t first this growth was white or dirty white, but after some days (three to 
ten) it became brown, and finally, in places, nearly or quite black (smoke 
brown is perhaps the proper term). The growth on potato was not wrinkled. 
The substratum and the fluid in the bottom of the tube also became brown. 
The rapidity and the degree of pigmentation seem to depend on the slightly 
varying composition of the potato, apparently on the amount of glucose 
present. No gas was formed in any of the many potato cultures. No acid 
was detected in any stage of the growth of the cultures, not even when tested 
at the end of the first twenty-four hours. The potato cultures, which were 
slightly acid on the start (mormal acidity of the tuber), soon became strongly 
alkaline to litmus paper. With Nessler’s solution the alkaline potato cultures 
gave an immediate, copious, orange-yellow reaction, indicating ammonia. 
These cultures developed a peculiar odor, often noticed in rotting potatoes, 
but not specially disagreeable. This odor was likened by one person to the 
smell of sour bran. Its chemical nature has, not been determined. The 
Sets did not fall into pieces, but retained their shape for several 
weeks. 
‘Gas Production.—No gas appeared in any of the many cultures. The 
organism is not a gas producer. 
‘* Relation to Oxygen.—This bacillus appears to be strictly aérobic. If 
aes uate anaérobic, itis not so with any of the carbohydrates yet 
tested. 
‘* Acids—No acid reaction could be detected in any stage of any of the 
cultures. Potato cultures only twenty-four hours old and which were acid 
on the start (normal acidity of the tuber) gave a decided alkaline reaction to 
litmus paper. If any acid whatever is formed it is masked by the presence 
of alkali and is not butyric acid. 
‘* Alkalies.—This organism is a very vigorous alkali producer. On 
warming the cultures over a gas flame or on placing the blued strips of 
litmus paper on a warm glass plate the alkaline reaction quickly disappears. 
On adding a few drops of Nessler’s reagent, as already stated, a copious 
orange-yellow precipitate is at once developed. This would indicate that at 
least a part of the alkali is due to ammonia. Probably amine bases are-also 
resent. 
. “‘The bacillus grows well in the thermostat at 87° C.—possibly a trifle 
better than outside at summer temperatures ranging from 25° to 32° C. 
Under either condition it grows rapidly. It still grew readily from bouillon 
cultures after several weeks’ exposure to 37°C. (three weeks’ exposure in 
one case, seven weeks’ exposure in another). 
‘* Pigments.—A brown pigment is formed in course of a few days in the 
host plants (potato, tomato, etc.), and in culture media containing grape, 
fruit, or cane sugar (nutrient agar, steamed potato, fermentation tubes). 
This pigment is soluble in water and glycerin. It is insoluble in ethyl alco- 
hol, ether, chloroform, xylol, and carbon bisulphide.” 
“BACILLUS HYACINTHI (Wakker). 
‘« Pseudomonas hyacinthi (Wakker).—A yellow, rod-shaped organism, 
multiplying by fission ; ends rounded ; single, in pairs, or fours, more rarely 
in the form of chains or filaments; motile by means of one polar flagellum. 
In the host plant, when the bundles are crowded full of the yellow slime and 
broken down, it is generally 0.8 to 1.2 by 0.4 to 0.6. In alkaline beef 
broth or on agar it usually measures 1 to 2 by 0.4 to 0.6%, In old cultures 
rich in sugar it often grows out into long, slender chains, or into filaments 
(50 to 100“ long) in which there are no distinct septa. Non-sporiferous. Color 
distinctly yellow, but somewhat variable. Chrome yellow to pale cadmium 
in the host plant, 7.e., bright yellow (Ridgway’s nomenclature of colors). 
On culture media, when not interfered with by the brown pigment, generally 
