Limits in Hybridization 
19 
labrusca) were bagged in 1917 and dusted with pollen from G-52. From 
this work no fruit was obtained. 
In 1918 twenty-two flower clusters on the same native Labrusca vine 
were bagged and the flowers were dusted with pollen from 1-1. In the 
fall of the year fruit was taken from seven of the bags and a total of 83 
seeds was obtained. All of these seeds are the result of a cross because 
the mother vine which bears reflexed stamens has proven itself to be 
absolutely self-sterile.* 
In 1918 eleven flower clusters on the variety Lutie (Y. labrusca) were 
prepared, bagged and dusted with pollen from 1-1. From this work 283 
seeds have been obtained. These seeds will be planted in 1919 and the 
hybrid character of the seedlings noted. 
Vitis Rotundifolia X Vitis Labrusca 
In 1917 four flower clusters on 1-1 were prepared, bagged and polli¬ 
nated with Concord pollen. No fruits developed from this work. 
In 1918 six flower clusters on a forced Scuppernong vine were bagged 
and pollinated with Lutie pollen. Again no fruits developed. 
From the results of this work we again see a difficulty in securing the 
reciprocal cross, Y. rotundifolia x Y. labrusca. 
Vitis VEstivalis X Vitis Rotundifolia 
In 1918 nine flower clusters on a native imperfect hermaphroditic Aes¬ 
tivalis vine were bagged and cross-pollinated with pollen from 1-1. In 
eight of these bags no fruit developed and in the ninth bag a small 
cluster of apparently normal fruit developed. This cluster yielded 20 
seeds which will be planted, and the resulting seedlings will be keenly 
watched and examined for hybrid characters.! 
Vitis Rotundifolia X Vitis 2E stir alls 
In 1917 one flower cluster on a seedling Rotundifolia vine, H-28, one 
on another seedling, K-19, and seven on Scuppernong were bagged and 
dusted with fresh pollen from a staminate Aestivalis vine. ISTo fruits 
developed in any of these bags. 
In 1918 eight flower clusters on Scuppernong and ten on the variety 
James were bagged and treated as before. The bags on the Scuppernong 
vine yielded no fruit while only one bag on the James vine yielded but 
two berries. It is to be regretted that this bag, together with its contents, 
disappeared just when the fruit was ripening on the vine. 
* Since the manuscript for this bulletin was prepared these seeds have germinated and 
after a careful examination of them all possible doubt as to their hybrid nature has been 
dispelled. 
t Since the manuscript for this bulletin was written these seeds were planted and nine¬ 
teen of them germinated. Most of these seedlings are constitutionally weak and thus far 
only nine have survived, but all of them have proved to be true hybrids with Vitis rotun¬ 
difolia. 
