176 
Journal of Agricultural Research 
Vol. XXIX, No. 4 
After this one-half hour treatment 
the solutions were poured off and part 
of the corms planted at once in sterile 
soil. The others were allowed to dry. 
When the corms had dried, lesions 
were taken from all the lots and isola¬ 
tion plates made without any further 
sterilization, but each lesion was washed 
through three changes of sterile water 
to remove any disinfectant that might 
be on the surface. 
Bacterium marginatum was secured 
from husks of the corms treated with 
mercuric chloride, but considering the 
heavy inoculation of the plates, there 
were not many viable bacteria in these 
husks. No Bacterium marginatum was 
obtained from the husks of the other 
three lots or from corm spots of any of 
the four. A small number of bacteria 
and fungi of several sorts appeared in 
the plates. In general, there was a 
striking reduction in the number of 
organ isms. 
Three weeks after treatment the rest 
of the corms were planted in pots of 
sterile soil. All the corms produced 
healthy, vigorous plants. Six months 
later when they were dug the new 
corms and cormlets were free from 
spots, except a few in the lot treated 
with copper sulphate, which had slight 
but definite husk lesions. 
In another experiment typically 
pitted corms of the varieties Mrs. 
Frank Pendleton, Mrs. Francis King, 
Schwaben, America, and a few of un¬ 
known variety, were treated for 1J^ 
hours in formalin 1-60, then planted 
while still damp in clean soil in pots. 
There were 80 corms in this lot and the 
husks were not removed. All grew 
well and produced vigorous plants. 
Four and a half months later a few 
were blooming and in most the new 
corm was fairly well developed. No 
sign of infection was found on leaf parts 
or on corms. 
Sixty healthy corms were treated the 
same as the pitted corms. Fifty were 
planted in sterile soil and ten in soil 
taken from a bed where the bacterial dis¬ 
ease had occurred the previous season. 
Those in sterile soil produced clean 
plants and corms. Those in the in¬ 
fected garden soil had no infection on 
the parts aboveground, but the “neck” 
and new corm of all showed typical 
spots after 5 months’ growth and isola¬ 
tion plates produced typical colonies 
of Bacterium marginatum. Special 
effort was made to keep the soil surface 
firm and there was practically no soiling 
of the lower leaves. 
OTHER HOSTS 
On iris a very weak infection oc¬ 
curred if the inoculated areas were 
kept moist for several days. The 
spots caused by the bacteria were 
reddish-brown surrounded by a water- 
soaked area. 
Calla lily leaves and petioles were 
inoculated but never showed any 
infection. 
OTHER BACTERIAL DISEASES OF 
THE GLADIOLUS 
In 1913 G. Severini (10) published 
descriptions of two bacterial diseases 
of gladioli. Both are soft rots at¬ 
tacking chiefly the underground parts 
of the plants. Neither of these 
organisms, Bacillus ixiae G. S., and 
Pseudomonas gladioli G. S., in morpho¬ 
logical or in cultural characters is like' 
the organism, Bacterium marginatum, 
described in this paper. 
Prillieux and Delacroix (6 p. 670) 
have published a very brief note 
concerning deeply corroded brown 
spots on the roots of “Glaieul”. A 
short, very motile bacillus was found 
in the tissues. In bouillon cultures 
no color change took place in the 
medium. No name was given the 
organism and no further description 
has been found concerning this 
bacillus. 
Rostrup (8, p. Ji.73; 9, p. 175) refers 
to a disease of hyacinth and gladiolus 
which causes yellow stripes on the 
leaves in which bacteria have been 
found. 
A yellow bacterium causing trans¬ 
lucent spots on gladiolus leaves was 
described in 1924 by McCulloch ( 8 ). 
The appearance of the lesions and the 
characteristics of the causal organism 
are quite unlike Bacterium marginatum. 
Mizusawa ( 5) reports a disease on 
crocus due to Bacillus Croci Mizusawa, 
and his photographs of colonies re¬ 
semble Bacterium marginatum but the 
cultural characters and morphology 
of the bacteria are unlike Bad. margi¬ 
natum. 
Wallace (11) refers briefly to a dis¬ 
ease of gladiolus, “a soft rot probably 
caused by bacteria.” No description 
is given of the disease or the organism. 
SUMMARY 
The bacterial disease of gladiolus 
described in this paper has been under 
observation for several years in the 
