New York AGRICULTURAL EXPERIMENT STATION. 73 
pathogenicity of a number of these cultures was tested by inocu- 
lating healthy cabbage plants. These plants were grown in the 
greenhouse and were inoculated with all precautions necessary 
to prevent the entrance of other germs. Several check plants 
were treated in the same way in all respects except that they 
were pierced with a sterile needle instead of one dipped into 
a bacterial culture. Two plants were inoculated with each culture 
and eight cultures were tested representing two tubes from the 
November, three tubes from the December, and three tubes from 
the February examination. Two cultures were from tubes which 
had been paraffined and six from unparaffined tubes. 
April 15, the characteristic symptoms of black rot were show- 
ing in fourteen of the sixteen inoculated plants. May 7, the dis- 
ease was very evident in all of the inoculated plants. In order 
to complete the proof that the diseased condition of the plants 
was really due to the germ inoculated, cultures were made from 
the diseased tissue in three plants representing a like number of 
the original eight cultures and P. campestris found in pure cul- 
ture. The check plants which had grown beside the inoculated 
ones all remained healthy. 
April 26, each of the two cultures obtained from the examina- 
tions of April 4, was inoculated into two young cabbage plants 
in the greenhouse with all necessary precautions. The plants 
were growing rapidly and the temperature in the greenhouse 
was high. May 3, the disease was showing in two of the inoculated 
plants and May 7, it was evident in all four of them. Cultures 
were made from the tissue of these plants and P. campestris 
obtained. The two control plants remained healthy. The accom- 
panying plate (Plate I) shows one of these control plants as well 
as one inoculated with the culture of P. campestris. A number 
of leaves have already been destroyed with the characteristic 
lesions of black rot. The photograph was taken one month after 
the inoculation. 
REPETITION OF THE TEST ON CABBAGE SEED. 
Oct. 17, 1903, a second lot of cabbage seed was infected as 
nearly as possible in the same manner as in the first test using 
the same strain of P. campestris. In this test ten seeds were 
placed in each test tube, 
