THE MOSAIC DISEASE OF CUCURBITS. 
33 
. ber, the trichomes of mosaic and healthy leaves being brought in 
contact in such a way as to merely break the trichomes without 
injuring the epidermis of the leaf. Infection has resulted in most 
of the plants thus inoculated, as is shown in Table X. 
Table X. — Infection as a result of contact of trichomes of leaves of healthy and mosaic 
far cucumber plants. 
Treatment. 
Number 
of 
plants 
inocu- 
lated. 
Results. 
Date 
inoculated. 
Number 
of 
mosaic 
plants. 
Date last 
observed. 
Apr. 20,1916 
Do 
2 
2 
6 
4 
12 
12 
10 
8 
4 
4 
12 
6 
2 

4 

9 

5 

2 

3 

Apr. 28,1916 
Do 
Healthy leaves in contact (control) 
Aug. 5, 1916 
Do 
Aug. 10,1916 
Do 
Feb. 21,1917 
Mar 2 19i 7 
Do 
Do 
Mar. 22, 1917 
Apr. 4, 1917 
Do 
Do 
June 20, 1917 
June 28 1917 
Do 
Do.' 
Oct. 24, 1917 
Nov 2 1917 
Do...- ... 
Do.' 
BLOSSOM INOCULATIONS. 
No evidence has been obtained thus far which indicates infection 
through the blossoms. Numerous inoculations of male and female 
flower parts were made by pricking the expressed juice of a mosaic 
cucumber plant into the petals, stigmas, or anthers of the blossoms 
of healthy cucumber plants. From 3 to 8 blossoms on each of 38 
plants have been inoculated in this way, but no infection has ever 
occurred. It is still a question, however, whether such infection may 
not occur, especially as the virus is known to be present in the blos- 
soms of mosaic plants, as is shown on page 35. 
FRUIT INOCULATIONS. 
Inoculations into small fruits have given infection in a number of 
plants, as is shown in Table XI, but inoculations of fruits approaching 
maturity were nearly always unsuccessful. 
Table XI. — Results of inoculation of fruits of healthy cucumber plants. 
Treatment. 
Inoculum. 
Approxi- 
mate age 
of fruits 
inoculated. 
Number 
of fruits 
inocu- 
lated per 
plant. 
Number 
of plants 
inocu- 
lated. 
Results. 
Date inocu- 
lated. 
Number 
of mosaic 
plants. 
Date last ob- 
served. 
Mar. 20,1916 
Do 
Aug. 20,1917 
Do 
Inoculated . . . 
Control 
Inoculated . . . 
do... 
Expressed juice of 
mosaic plant. 
Expressed juice of 
healthy plant. 
Expressed juice of 
mosaic plant. 
..do 
10 days.... 
....do 
5 days 
21 days.... 
5 weeks . . . 
....do 
2 
2 
2 
2 
2 
1 
2 
2 
1 
2 
6 
6 
8 
8 
3 
7 
10 
5 
4 
8 
3 

3 
3 

1 

3 
1 

Apr. 5, 1916 
Do. 
Sept. 5,1917 
Do. 
Do 
do 
....do 
Do. 
Do. 
. do 
...do... 
Do. 
Do 
Apr. 12,1918 
Do 
Control 
Inoculated . . . 
do 
Expressed juice of 
healthy plant. 
Expressed juice of 
mosaic plant. 
do 
10 days — 
7 days 
21 da vs.... 
7 day's 
Do. 
May 3, 1918 
Do. 
Do 
Control 
Expressed juice of 
healthy plant. 
Do. 
185118°— 2( 
