16 BULLETIX 1074, U. S. DEPAETMEXT OF AGRICULTURE. 
contained valuable information on the origin of domestic varieties. 
Agricultural papers have been reviewed, and much information as to 
the origin of varieties has been obtained from that source. There is 
still much to learn concerning the origin of our cultivated varieties. 
The origin of many probably has never been recorded, but of some 
for which the origin has not been determined there probably is a 
recorded history somewhere. Eeference is always given to the pub- 
lished sources of the histories that have been obtained. 
DETERMINATION OF DISTRIBUTION OF VARIETIES. 
The commercial distribution and production of different varieties 
are the greatest economic factors with which this classification is con- 
cerned. Those varieties which are most widely grown usually are the 
most valuable. Varieties that are more productive may be in exist- 
ence, but until they become known and widely grown they are of little 
value. Xew varieties are being continually produced. Some are of 
little or no value. Others are an improvement over the older stand- 
ard varieties, as their use extends the area of wheat culture, increases 
the yield per acre, or improves the quality. This adds to production 
and increases the income of the producer. 
The commercial success of varieties is largely dependent upon their 
adaptation to the conditions in which they are grown. A variety 
that produces well in a locality soon becomes well known and its 
acreage increases until it comes into competition with other varieties 
which are more productive. The production of old, well-adapted 
varieties is rather extensive and stable. Their distribution has be- 
come fixed within certain general sections. Xew varieties are still 
competing for supremacy and therefore are more locally and spar- 
ingly grown. Poorly adapted varietLes sometimes have continued in 
cultivation for more than a century in isolated and unimportant 
wheat-producing localities. The distribution of these, therefore, is 
often widely scattered. 
THE VARIETAL SURVEY. 
To determine the commercially cultivated varieties of wheat in 
the United States and the extent of their distribution, a wheat 
varietal survey was made in cooperation with the Bureau of Crop 
Estimates. The first survey was made in 1917, when questionnaires 
were sent to one or two correspondents in each of the wheat- produc- 
ing counties of the various States. The incomplete returns from 
this survey were very interesting and contained so much valuable 
information from the counties reporting that it was decided in 1918 
to send questionnaires to several correspondents in all counties not 
previously reporting, in order to have a more complete record. 
The replies were received and tabulated. They showed the varieties 
