254 
Journal of Agricultural Research 
Vol. V, No. 6 
in the filaments, anthers, and pistils of blossoms produced by affected 
plants. See Table II. 
Tabus II .—Occurrence of virus in the filaments , anthers, and pistils of blossoms produced 
by tobacco plants affected with the mosaic disease * 
Date of 
inocu¬ 
lation. . 
Number of 
plants. 
Variety. 
Material used for inoculation. 
Effect. 
1914. 
May 2i 
10. ... 
Maryland Mammoth . 
Sap of macerated pistils ex- 
10 affected with mosaic 
21 
21 
10. 
10 (control).. 
tracted very carefully with 
forceps from the blossoms of 
a tobacco plant affected with 
mosaic disease. A gentle 
pull with the forceps readily 
severs the style at its junction 
with the apex of the ovary. 
Sap of leaves of the same plant, 
A. 
Sap of the leaves and pistils of 
a healthy plant. 
disease on May 28. 
Do. 
All healthy on May 28. 
Experiments with the pistils of plants affected with the mosaic disease 
were again repeated, using only the upper portion of the style and the 
stigma. This was done to avoid the possibility of infection from tissues 
of the ovary adhering to the base of the style when extracted. See 
Table III. 
TabeE III. — Occurrence of virus in the upper portions of the filaments , anthers , and 
pistils of blossoms produced by tobacco plants affected with the mosaic disease 
Date of 
inocula¬ 
tion. 
Number of 
plants. 
Variety. 
Material used for inoculation. 
10. 
Maryland Mammoth.. 
Macerated upper portions of 
pistils from plants affected 
with mosaic disease. 
10. 
.do. 
Sap of leaves of the same plants. 
10 (control).. 
Sap of leaves and upper portions 
of the pistils of healthy plants. 
10. 
Sap of anthers of plants affected 
with mosaic disease. These 
anthers were carefully re¬ 
moved with forceps just prior 
to opening, and were macer¬ 
ated in a mortar with a small 
quantity of clean tap water 
sufficient to make a thin paste. 
10 (control).. 
.do. 
Sap of anthers of healthy plants 
extracted in the same man¬ 
ner. 
1914 
May 27 
27 
27 
June 2 
Effect. 
S affected with mosaic 
disease on June 6. 
10 affected with mosaic 
disease on June 6. 
All healthy on June 6. 
10 affected with mosaic 
disease on June 10. 
All healthy on June 10. 
From the preceding experimental data it is evident that the virus of 
the mosaic disease in affected plants becomes distributed throughout 
the placental structures, reaching even the ovules themselves. Whether 
the virus passes beyond the integuments of the ovules to the embryo sac 
has not been determined. There is some indication that the macerated 
placenta in a succulent condition is more effective than the immature 
