476 BOTANICAL GAZETTE [JUNE 
where tomato mosaic had occurred in previous years. On May 
24, 1921, an examination was made in and near the experimental 
field at Frankfort which had been in tomatoes in 1919, and in which 
mosaic was found on the Physalis plants in 1920. In the old tomato 
field, 147 out of 203 Physalis plants examined (or 74 per cent) 
showed mosaic. The disease occurred more generally distributed 
throughout the field, and on a much higher percentage of the 
plants than in 1919 and 1920. In the manner characteristic of 
the perennial species of Physalis, many of the plants occurred in 
clumps, and as a rule the plants in each clump were all healthy or 
all mosaic. 
In the field west of the old tomato field, 11 out of 179, or 6 per 
cent of the Physalis plants examined in a strip about so feet wide 
along the fence showed mosaic. In the fields east of the old 
tomato field, 11 out of 39, or 29 per cent of the Physalis plants 
examined showed mosaic. In the field to the north, no mosaic 
was found on the 66 plants examined, but most of these were at a 
considerable distance from the tomato field. From these mosaic 
Physalis plants the disease was transmitted to tomato plants in 
e greenhouse, as noted in a previous paragraph. In this area, 
therefore, the mosaic disease persisted in Physalis plants two years 
after the tomatoes, and even became more prevalent on the weeds. 
On May 23, 1921, mosaic Physalis plants were found in a small 
plot and in a field near Lafayette, in both of which tomato mosaic 
had occurred in 1920. On May 25, 1921, a study was made of the 
Physalis plants in a three-acre field near Indianapolis in which 
tomato mosaic had been especially severe in 1920. On one side 
of the field, 6 out of 209 Physalis plants examined showed mosaic, 
and on the other side, 67 out of 159 showed mosaic. Thus a total 
of 73 out of 368, or 20 per cent of the Physalis plants were affected 
with mosaic. No mosaic had been noted on the Physalis plants 
among the tomatoes in this field on September 14 of the preceding 
fall. In an adjacent portion of this field which had been in corn 
in 1920, 104 Physalis plants were examined and none showed 
mosaic. 
These observations showed that the mosaic Physalis shoots were 
appearing rather generally in fields which had been in tomatoes in 
