26 
The Bulletin 
the wild, the grape is dioecious, and fertile pollen borne by the pistillate 
flower with reflexed stamens is rare, if it occurs at all.” 
Among the many vines of Yitis rotundifolia, both the cultivated and 
the wild, that have been studied at this Station, not one case has been 
discovered where normal fruit is definitely known to have developed 
from pollen that was produced by the reflexed type of stamen/" 
The production of seedless berries must naturally be omitted from 
the present discussion, because it is not the result of a sexual union be¬ 
tween two normal gametes, and it is not the purpose of this bulletin to 
discuss parthenocarpy in relation to the pollination of flowers. 
That all vines of Yitis rotundifolia which bear the reflexed type of 
stamen are completely self-sterile is borne out by the published results 
in Bui. ISTo. 209 (1). To these results we can add from Tech. Bui. ISTo. 
10 (5), that when 693 seedlings were raised from Scuppernong crossed 
by a male vine homozygous for dark color, not one light-colored vine 
appeared in the whole lot. It will be remembered that in crossing varie¬ 
ties of rotundifolia grapes which have the reflexed type of stamen, the 
usual emasculation, process is habitually omitted, because if any fertile 
pollen were produced, its presence could quickly be detected in the 
progeny of such a cross by the presence of light-colored seedlings. Like¬ 
wise, the 62 seedlings from James crossed with the same dark male vine 
were all dark in color, notwithstanding the heterozygous nature of the 
James variety with respect to light and dark colors. 
The correlation of upright stamens with viable pollen and self-fer¬ 
tility of the grape is also generally recognized. While the introduction 
of rotundifolia grape vines that bear upright stamens is of recent date 
[Beimer and Detjen (1), and Husmann and Dearing (4)], all have 
proved to be self-fertile, at least in varying degrees, and consistent with 
the small fruit clusters of this type of grape. Hope, our original wild 
vine, and its vegetative offspring, in some years under favorable condi¬ 
tions, has proven to be self-fertile, as recorded elsewhere in this bulletin. 
All of the perfect flowered seedlings of this same vine, the founder of 
our race of self-fertile rotundifolia grape vines, also produce normal 
viable pollen like their parent and are self-fertile in the same degree. 
Husmann and Dearing (4) report that both of their original seedlings 
with upright stamens are fruitful and self-fertile. Also, that all of 
their more recent seedlings of similar character are likewise self-fertile. 
In 1915 flower clusters on a number of perfect flowered seedling vines 
were bagged for a test of their self-fertility. The bags happened to be 
distributed as follows: one bag on each of 64 different vines, six bags 
on one special vine, and eighteen on another special vine. The results 
obtained are presented in the following table. 
*The two berries that are mentioned in Bui. 209 of this Station as having developed 
under closed cloth bags on a Scuppernong vine are regarded, in the light of more recent 
investigation, as the result of cross-pollination, which must have taken place previously to the 
bagging operation. That a single flower in the bag which covered several hundred similar 
flowers should receive sufficient pollen to produce three or four seeds, as was found in this 
case, while other flowers under the same bag by laws of chance should receive absolutely 
none, appears almost incredible. It is much easier to conceive of two fertilized blooms having 
been overlooked in the examination and preparation of the many thousands of buds that were 
covered in the experiment. 
