10 BULLETIN 1074, U. S. DEPARTMENT OF AGRICULTURE. 
to the extent of reduction of the number of species, these authors 
still maintained a complete Latin nomenclature for forms as far 
as the fifth rank. In their discussions, these authors, as well as 
other investigators named, were handicapped through making their 
studies in only one locality. In the present work, the varietal de- 
scriptions are based on the expression of each variety under the 
widely varying conditions of environment found in different parts 
of the United States. 
PRESENT INVESTIGATIONS. 
The present investigations were started in 1915? with the object 
of making a classification of the wheats of the world. During the 
first two years much time was devoted to a study of foreign varieties, 
and several hundred introductions were added to the large collection 
of foreign wheats previously obtained. In the third year the study 
was devoted largely to diverse botanical types obtained from hy- 
brids or distinct types found as mixtures in wheat fields in the west- 
ern United States. It was soon determined, however, that if the 
studies were to be of economic value, they must be limited to the 
principal cultivated varieties. The World War prevented the com- 
pletion of the introduction of foreign wheats, so it was finally de- 
cided to limit the present publication to the commercial American 
varieties. In the spring of 1919, a “ Preliminary classification of 
American wheat varieties,” * containing a key to varieties and index, 
was prepared in mimeograph form, and about 100 copies distributed 
to agronomic workers. Suggestions and corrections were invited. 
Several changes which were suggested have been incorporated. 
Hundreds of foreign and domestic varieties have been grown, 
studied, described, and classified, and herbarium specimens have been 
preserved in a classified order. Many of these varieties, however, 
are not included in this bulletin. During the past three years the 
°>The plan to classify wheat varieties was evolved by Carleton R. Ball, agronomist 
in charge of Western Wheat Investigations, in the summer of 1914, while studying a large 
number of foreign and domestic varieties in breeding nurseries at experiment stations in 
the western United States. In July of that year J. Allen Clark became his assistant, 
and the classification was carried on jointly until April, 1918, when Mr. Ball was pro- 
moted to the position of cerealist in charge. Since that time the classification has been 
continued by Mr. Clark, who was placed in charge of Western Wheat Investigations, and 
by John H. Martin, who became his assistant in February, 1919. 
During the entire investigation the fullest cooperation has been received from Dr. C. E. 
Leighty, agronomist in charge of Eastern Wheat Investigations, who has furnished numer- 
ous varieties, much information on varietal history and synonymy, and some assistance 
with the nurseries in the Eastern States. ; 
In the preparation of the manuscript of this classification C. W. Warburton has 
rendered valuable editorial assistance. The drawings were made by Mrs. R. BE. Gamble 
and the photographs, unless otherwise indicated, were taken by H. L. Crandall. These 
services are all gratefully acknowledged. 
* Clark, J. Allen, Ball, Carleton R., et al. Preliminary classification of American wheat 
varieties, 20 p. 1919. (U.S. Dept. Agr., Off. Cereal Invest. Mimeographed circ.) 
