40 
wild forms from Trans-Caucasia, Abyssinia, western China, Per- 
sia, and Palestine. These have been grown in the plant-breeding 
plots of the Garden, and in bench and pot cultures in the green- 
house. Herbarium material has been collected from them and 
pure strains have been isolated. Hundreds of crosses between 
these strains and varieties have been made from which thousands 
of new forms have been obtained, some of which may prove to 
be better adapted to our climatic conditions through their ability 
to stand hot weather. 
Studies on the inheritance and nature of productiveness in peas 
are being emphasized, as well as the relation of different environ- 
ments to this and to other pea characters. Eventually, through 
these studies, it is hoped to make known the manner of inheri- 
tance of all the character differences in peas and, from this knowl- 
edge, to be able to synthesize a desired variety by bringing to- 
gether certain characters through crossing, much as one does in 
chemistry in making desired compounds. Material as favorable 
for the theoretical study of the laws of heredity as are peas, 1s 
rare, and it is needless to point out how obviously agricultural 
and horticultural breeding is dependent on theoretical studies of 
heredity. Practical plant-breeding such as that of Lemoiue, 
Burbank, and others would not now be possible if it were not for 
the theoretical studies made during the preceding centuries, any 
more than it would be practicable or possible to build bridges 
without our present knowledge of the laws of physics. 
The experiments on castor beans involve the same aims as 
those mentioned for peas, though special emphasis is being laid on 
several characters of economic importance having to do with 
their value as ornamental and oil producing plants. 
In addition to the experimental work on peas and castor beans, 
Miss Stella G. Streeter is investigating, under Dr. White’s direc- 
tion, the heredity of various characters in corn, several of which 
involve productiveness. About thirty very distinct varieties ot 
corn are usually grown on the grounds for experimental purposes. 
At present the plant breeding and heredity work is much ham- 
pered through lack of sufficient greenhouse space for growing 
winter cultures, and through insufficient clerical and gardening 
assistance for keeping pedigree records and taking proper care of 
