6 o 
Journal of Agricultural Research 
Vol. II, No. i 
In three days some of the spots were beginning to enlarge, and in seven days the 
results were as shown in Table II. 
Table; II .—Results of inoculation experiments of July 28 on York Imperial apple 
branches. 
Experiment No. 
Number 
of burned 
spots. 
Number of 
enlarge¬ 
ments. 
Percentage 
of enlarged 
spots. 
I . 
IOI 
66 
6s 
9 
O 
2... 
94 
4 i 
82 
8 
2 . 
0 
4. 
46 
Of 15 reisolation cultures from experiment 4, 12 developed Altemaria in pure cul¬ 
ture and 3 contained only bacteria. Out of 18 cultures from spot enlargements of 
Nos. 1 and 2, 15 contained pure cultures of the Alternaria and 3 were sterile. 
No counts of spot enlargements were made in the experiments of August 5, but it 
was noted that in those cases in which leaves were treated with alcohol and with 
mereuric-chlorid solution or with the mercuric-chlorid solution alone there were con¬ 
siderably fewer enlargements than in those untreated or those sterilized and inoculated 
with Alternaria spores or treated with alcohol alone. All the branches were placed 
under bell jars lined with wet filter paper. 
The experiments of August 9 were carried on as follows: 
Experiment i. —York Imperial apple branches were placed in 95 per cent alcohol 
for a moment, in mercuric-chlorid solution (1 to 1,000) for three minutes, and in sterile 
water for five minutes. Spots were then burned on the leaves, and, after being 
drenched with sterile water, the branches with their cut ends in a flask of water were 
placed under a bell jar lined with wet filter paper. 
Experiment 2.—Same as experiment 1 except that treatment with mercuric- 
chlorid solution was omitted. 
Experiment 3.—Same as experiment 1 except that immersion in alcohol was 
omitted. 
Experiment 4.—Treatment was the same as in experiment 1, but in addition the 
leaves were sprayed with sterile water containing spores of Altemaria isolated from 
enlarged spots of experiment of July 8. 
Experiment 5.—Spots were made with a heated rod, as in the other experiments, 
and the leaves drenched with sterile water. The branches were then placed under a 
bell jar lined with wet filter paper, as in the preceding experiments. The results are 
given in Table III. 
Table III .—Results of inoculation experiments of August Q on York Imperial apple 
* branches . 
Experiment N 0. 
Number 
of burned 
Width of 
enlarge¬ 
ments. 
Number of enlarged spots. 
Percentage of enlarged spots. 
spots. 
Aug. 14. 
Aug. 16. 
Aug. 18. 
Aug. 14. 
Aug. 16. 
Aug. 18. 
I. .. 
216 
Mm. 
2 to 4 
15 
IS 
15 
7 
7 
7 
2. 
162 
2 to 4 
9 
40 
77 
6 
25 
48 
3 . 
215 
2 tO 4 
10 
17 
26 
5 
8 
12 
4 . 
192 
2 tO 4 
81 
8r 
162 
42 
42 
84 
5 . 
105 
2 tO 4 
38 
38 
61 
36 
36 
58 
Cultures were made from enlarged portions of spots from experiments 2, 4, and 5. 
In each case marginal parts of the dead tissue were cut out, placed for a moment in 
95 per cent alcohol, then in mercuric-chlorid solution (1 to 1,000) for three minutes, 
and in sterile water for five minutes. Of n cultures from experiment 2, 6 developed 
