Jan. is, 1917 
Blackleg Disease of Potato 
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these agar slants in 24 hours after being inoculated with a single stroke 
of a straight needle there was no visible growth. In 48 hours and later 
it was well defined and of uniform appearance in the case of B. atro - 
septicus , B. solanisaprus , B. melanogenes , IIIA, SE, and IIP. The 
character of the growth may be described as moderate, filiform, flat to 
slightly raised, smooth, glistening, plainly opalsecent, later opaque, 
color whitish or pearly, later creamy, odor absent, consistency buty- 
rous—slightly viscid in the case of B. solanisaprus and B. melanogenes . 
The two strains carried as B . phytophthorus produced only a very faint, 
semitransparent, filiform growth on this medium. No discoloration of 
the medium was observed in either case. 
Cohn’s solution. —No growth was obtained with any of the organisms 
when inoculated into Cohn’s solution. 
Uschinsky’s solution. —The organisms received from Dr. Schuster 
as B. phytophthorus gave little evidence of growth in this medium, while 
all of the others produced a copious growth and behaved alike in it. 
Visible clouding with the latter was less during the first 24 hours than 
in broth tubes inoculated at the same time, but at the end of three days 
the medium was quite heavily clouded and milky in appearance. 
Sodium chlorid in bouillon. —One, two, three, four, and five gm. of 
sodium chlorid to each 100 c. c. of culture media were added to neutral 
beef infusion bouillon and narrow tubes each containing 5 c. c. of this 
salted medium were inoculated with a 2-mm. loop in the usual way. 
At the end of 18 hours there appeared to be no inhibition of growth of 
any of the cultures in the tubes containing 1 and 2 per cent of sodium 
chlorid. In 3 per cent, all were slightly but plainly less clouded than the 
check tubes inoculated at the same time, and no growth had appeared 
in the 4 and 5 per cent. At the end of 48 hours all the tubes containing 
3 per cent of sodium chlorid were apparently as well clouded as the 
checks. All showed growth in the presence of 4 per cent, but with some 
inhibition. In 5 per cent no growth was apparent in any of the tubes 
except those of B . phytophthorus from Appel, which showed about half¬ 
normal clouding for bouillon cultures of the same age. In three days B. 
atrosepticus , B . solanisaprus , B. melanogenes , IIIA, SE, and IIP in 5 per 
cent of sodium chlorid showed a faint but well-defined clouding for the 
first time and appeared quite uniform in appearance. B. phytophthorus 
from Appel was quite heavily clouded, while no growth could be detected 
in the culture of B. phytophthorus from Schuster. 
Growth in bouillon over chloroform. —This test was made with 
tubes containing 10 c. c. of sterile bouillon into each of which were intro¬ 
duced 5 c. c. of chloroform and the whole thoroughly agitated at inter¬ 
vals for two days. After allowing the tubes to incubate for several days 
to prove sterility they were inoculated with a 2-mm. loop of broth cul¬ 
ture in the usual way, care being taken this time to agitate the medium 
