61 
the season) it is hoped that height growth may be increased by 
this second dose of the American parent. 
New Ilybrids in 1934.—Another important development of our 
work in 1934 has been the production of new hybrids. Inci- 
dentally, it should be stated that all of the hybridization work this 
year was carried on at the trial grounds at Hamden, because 
many of the trees there have now reached the age of bearing 
flowers and nuts. The pollen used for crossing was in all cases 
carefully bagged before the anthers dehisced, for there is of course 
danger of contamination from various causes—chiefly insects and 
wind. The American pollen (of Castanea dentata), which was 
supplied as usual through the cordial cooperation of the Division 
of Forest Pathology, U. S. D. A., had also been bagged at an 
early stage. The hybrids produced in 1934 (at least as far as the 
embryo stage in the nuts) are as follows: 
(1) 2 Smith hybrids (Jap. * Amer. 7.e. crenata X dentata, 
3 yrs.*) crossed with American chestnut (U. S. 
Dy.) 
(2) 12 Chinese chestnut (C. mollissima, 8 yrs.) crossed with 
Castanea dentata (U.S. D. A 
(3) 19 Chinese chestnut (C. mollissima, var. Mammoth, 6 
yrs.) crossed with American Chestnut (U.S. D. A.) 
(4) 7 Chinese chestnut (C. mollissima, 8 yrs.) crossed with 
Castanea Seguinii (8 yrs.) 
(5) 4 Chinese-chinquapin hybrids (mollissima & pumila) 6 
yrs., crossed with American chestnut (U.S. D. A.) 
(6) 4 Japanese forest type (C. crenata var., 6 yrs.) crossed 
with American chestnut (U. S. D. A.) 
(i) 8 “S8"” (8 yrs.) crossed with Japanese forest type 
chestnut. (C. crenate var., 6 yrs.) 
(8) 1 “58” (8 yrs.) crossed with American chestnut. (C. 
dentata) (U. S. D. A.) 
Giotalies7 
As far as can be ascertained from definite, published records, 
these combinations are all new to science. 
With the exception of the first case, which has already been 
explained, a few remarks about some of these crosses may be of 
*The ages of the parents as of 1934 are given, where possible, in 
parentheses. 
