468 
Journal of Agricultural Research 
Vol. VIII, No. 12 
in this way inoculations were made with bacteria which had never been 
in culture. A record made of the amount of disease in this row at the 
time of inoculation is shown in figure i, c. There were some infected 
plants, but not enough to interfere with the work as long as their loca¬ 
tion was known. Frequent examinations of the plants were made; and 
any idea of attenuation of the virility of the organism by artificial cul¬ 
turing proved unfounded, since few of the spots appeared in less than 
eight days and most of them later. A record taken on July 15 (fig. 1, c) 
shows how slight the inoculation was, probably because of the high dilu¬ 
tion of the bacterial suspension. No count was made, and no idea is 
now had of the number of bacteria per cubic centimeter of that sus¬ 
pension. 
It was fortunate, from the author’s viewpoint, that this experiment 
was arranged before the prolonged rainy period of July, in which rain 
fell on July 7 and almost every day afterwards until the 25th. During 
this time the effect of the two tropical hurricanes, which did considerable 
damage in the Gulf States, was felt, the wind blowing during all the time 
from the southeast. 
Observations made toward the end of July, allowing a time factor as 
long as we had in our first experiment, showed that the disease had spread 
to the northwest of the inoculated row with very little disease on the row 
to the east (fig. 1, c). Upon further examination of the plants in the first 
experiment the disease was found to have spread over the plants in the 
rows west of that inoculated (fig. 1, A ), the direction of spread having been 
reversed. Many of these plants were recorded as being free from disease 
on June 28, while on July 30 it was so abundant as to make careful count¬ 
ing needless. Consequently “1,000” is used to denote relatively a great 
amount of disease, more than 1,000 spots. The only obvious factor 
which is capable of such far-reaching action is the wind, and this only 
when sufficient moisture is present over the leaves to enable the bacteria 
to become detached from the colony within the diseased area, either 
through the stomata or from the surface of the spots. Even heavy dews 
afford sufficient moisture for this purpose, as has been demonstrated by 
experiment. 
Absorbent cotton, sterilized in a plugged Erlenmeyer flask, was carried 
to the field on two occasions in the early morning while the dew was pres¬ 
ent. Small bits of this were pulled off with forceps, and each bit placed 
upon the top side of the diseased leaves, not especially over lesions, but 
promiscuously upon the leaf. After these were placed, each was taken 
up and placed into a tube containing sterile water (a sterile water 
“blank”). These were taken to the laboratory, shaken thoroughly, and 
samples of the water plated in agar. In the first preliminary experiment 
5 out of 30 plates showed Bacterium malvacearum. In the second case, 
12 out of 84 plates showed the organism. It would seem that the close 
percentages (16 and 14) of these two experiments is merely coincidental; 
