Limits in Hybridization 
13 
2. Materials and Methods Used. 
In order to study the limits in hybridization of a particular species 
of plant, it becomes imperative to collect for study and use as many 
of its allied species, genera and hybrids as is practicable. Consequently, 
we have made a collection of as many of the varieties and species of 
Vitis and hybrids with Yitis rotundifolia and some species of Partheno- 
cissus and Ampelopsis as were possible to obtain and grow under our 
local conditions. Many of the species come from distant States, but most 
of these so far studied and to be reported on in this bulletin with the 
exception of Yitis vinifera and named varieties of other species are 
native vines of local habitat. The behavior of other species in hybridi¬ 
zation toward Yitis rotundifolia will be reported on in future publica¬ 
tions. 
The varieties, species and genera reported on in this bulletin are as 
follows: 
(a) Yitis rotundifolia. 
(b) Rotundifolia-Munsoniana hybrids. 
(c) Vinifera-Labrusca-iEstivalis hybrid, variety Winchell. 
(d) Yitis bourquiniana, variety Herbemont. 
(e) Yitis vinifera, variety Malaga and two of its seedlings. 
(f) Vitis labrusca, native species and the two varieties, Concord and Lutie. 
(g) Vitis cordifolia, native species. 
(h) Vitis cinerea, native species. 
(i) Vitis mstivalis, native species. 
(j) Parthenocissus quinquefolia (Planch.), native species (Virginia Creeper). 
(k) Parthenocissus tricuspidata (Planch.) (Boston Ivy). 
(l) Ampelopsis heterophylla (Sieb. & Zucc.), variety Elegans (Koch) 
(Variegated Ivy). 
The methods used in all of the hybridization work are those that are 
commonly in vogue (See also Breeding Southern Grapes, Journal of 
Heredity, Yol. YIII, Ho. 6). The bags employed for this work were 
made of what is commercially known as Pacific Lawn. 
3. Results Secured from 1912 to 1918, Inclusive. 
Vinifera--Labrusca-Mstivalis Hybrid Var. Winchell X Vitis 
Rotundifolia 
In 1912 Winchell (Yinifera-Labrusca-JEstivalis) vines were used as 
the female parent and a light-colored male vine (Rotundifolia) was 
used as the pollen parent. Out of 99 seeds, 34 plants were secured, but 
as the female parent vines were of a hermaphroditic and self-fertile 
variety, the number of hybrid vines in this lot was subject to some 
doubt. Because of the poor conditions existing in the seed-bed, most of 
the seedlings of this cross perished. Eleven vines were finally trans¬ 
planted to the nursery for study. Later on it developed that ten of these 
eleven seedling vines were direct selfed descendants of Winchell, but one 
