42 
Agricultural Experiment Station 
than those on the Euvitis parent, more or less intermediate in wrinkling 
of the surface and in gloss; marginal teeth are more intermediate in 
character and the pubescence is intermediate in amount and density. 
(See Eigs. 6, 12, 16, 17, 23, 24, 25 and 26.) 
Tendrils: Simple in Rotundifolia but occasionally bifid, varying in 
the hybrid from simple to strongly bifid, not generally simple. (See 
Eigs. 5, 11, 14, 15, 25 and 26.) 
Flower-clusters: Small in the staminate and perfect hermaphroditic 
vines and very small in the imperfect hermaphroditic vines of the 
Rotundifolia species; small in the staminate and perfect hermaphroditic 
vines and very small in the imperfect hermaphroditic vines of the 
hybrids. The Rotundifolia species in this case seems to practically 
dominate the size of the flower-clusters. Except for size, the flower- 
clusters seem more intermediate in character between the two parent 
species. (See Eigs. 7, 9, 11, 13, 15, 18 and 19.) 
Blooming period of vine's: In the E 1 hybrids the blooming period 
seems to practically fall midway between that of the two parent species. 
The only exception to this we find in our 1912 Winchell-Rotundifolia 
hybrid and in our 1913 Herbemont-Rotundifolia hybrid whose blooming 
periods practically coincide with that of the Rotundifolia species. 
Sterility of flowers : In the Rotundifolia species we find two types 
of flowers as regards sterility; the perfect hermaphroditic flowers may 
be said to be self-fertile, the staminate and imperfect hermaphroditic 
flowers are self-sterile, due to sex and intersexualism with attendant 
impotence. Among the flowers of the hybrid vines we find another 
type as regards sterility, namely, the one that is sterile because of 
hybridization. In the anthers of perfect hermaphroditic grape flowers 
we generally find normal pollen grains, but in the anthers of such flow¬ 
ers of the E x hybrids we find mostly irregular pollen grains; occasionally 
a normal grain is produced. (See Eigs. 10 and 20.) Again the ovules 
in perfect hermaphroditic grape flowers generally may be said to be 
fertile, but in the Fx hybrid the fertile ovule seems to be the exception, 
for out of all of the ovules from about twenty flower-clusters of this 
type of flower only two developed into fruit. The sterility of these 
ovules can easily be attributed to the hybrid origin of the vines. In 
the anthers of imperfect hermaphroditic grape flowers we generally find 
aborted pollen grains resulting from the phenomenon of intersexualism, 
but the ovules in such flowers are usually fertile. In the imperfect 
hermaphroditic flowers of the hybrids we find as usual aborted 
pollen grains in the anthers, but most of the ovules also are sterile: 
hence sterility in this case is due to the double phenomenon of inter¬ 
sexualism with attendant impotence, and hybridization. 
In the anthers of our staminate hybrid vine, Bourquiniana X Rotundi¬ 
folia, we again find mostly all aborted pollen grains, hence this vine 
also is practically sterile because of the double phenomenon of sex and 
hybridization. Sterility due to hybridization therefore seems charac- 
