4 
Journal of Agricultural Research 
Vol. XXXI, No. 1 
MUSKMELON 
Greenhouse Trials of 1920-21 
In addition to the trials with seed from mosaic cucumber plants, 
experiments were also conducted with seed from mosaic muskmelon 
plants, Cucumis melo L. As in the case of the cucumber, there had 
been field observations which suggested the possibility of seed trans¬ 
mission of the disease ( 8 ), but no actual experimental data had been 
obtained. Seeds from mosaic muskmelon plants were collected at 
Madison, Wis., during the summer of 1919, and an additional supply 
collected at Vincennes, Ind., was received from M. W. Gardner, of the 
Indiana Agricultural Experiment Station. 
The trials were made in the greenhouse at Madison, following the 
same procedure as that described above in the case ol the cueumber. 
Several series were conducted during the winters of 1920 and 1921, 
using seed from the same lot. The seeds were grown in duplicate 
series at air temperatures of 24° and 30° C. and the plants were kept 
under observation for approximately 30 days. Under these condi¬ 
tions 2,700 plants were grown until the third leaf had formed, but 
no symptoms of mosaic were noted on any of the plants grown at 
either temperature. 
SQUASH AND PUMPKIN 
Greenhouse Trials 
Although the trials with both the cucumber and muskmelon have 
yielded evidence almost wholly negative in regard to seed transmis¬ 
sion of mosaic, seeds from mosaic plants of the wild cucumber, 
Micrampelis lobata , have been shown to be carriers of the disease 
(7). In view of this peculiar circumstance, it was thought that the 
seeds of the larger-seeded cucurbits, such as Micrampelis, might be 
more likely to carry the virus than those of the smaller-seeded type, 
such as the cucumber and muskmelon. Experiments were therefore 
carried on in the greenhouses at Madison during the winter of 1921, 
in which seed from mosaic fruits of certain varieties of squash and 
pumpkin were grown in flats of sterilized soil at temperatures of 24° 
and 30° C., as in the earlier trials with seed from the cucumber and 
muskmelon. 
The seed used was collected during the summer of 1920 from 
mosaic fruits of the Large Cheese pumpkin, Cucurbita moschata 
Duchesne, the Summer Crookneck and Golden Custard squashes, 
Cucurbita pepo L., and the Hubbard squash, Cucurbita maxima 
Duchesne. The following numbers of plants were grown from seed 
from the different varieties: 
Summer Crookneck squash_ 475 
Golden Custard squash_ 270 
Hubbard squash_ 190 
Large Cheese pumpkin_ 180 
All of these plants were held until the third leaf had developed, 
and the growth, although somewhat elongated, appeared to be of 
normal character. No indications of mosaic were found on any of 
the plants of these varieties. 
The accumulated evidence of all trials with seed from mosaic 
plants of the cultivated cucurbits has been so overwhelmingly nega¬ 
tive that it seems evident that the seed of the cultivated varieties is 
