14 BULLETIN 1334^ TJ. S. DEPARTMENT OF AGEICULTUBE 
and growth, often contained similar observations. The annual reports 
from the Canadian experimental farms frequently contained notes in 
addition to the yield and growth data. These notes were of great 
assistance. The senior writer visited Ottawa and Charlottetown for 
the purpose of obtaining further information as to the nature of the 
varieties grown in Canada and at both places examined specimens of 
many of the varieties grown in the earlier 3'ears at these stations. 
Among these were many type specimens of Doctor Saunders's 
hybrids. The senior writer has been identified with barley studies 
in the United States since 1909. Certain varieties grown at that 
time have since disappeared, and the memorj^ of things seen even 10 
or 12 years ago has been serviceable. 
The"^ writers know that the identifications are far from perfect. 
The records at many places were inadequate. Some stations had 
conducted varietal experiments for 15 years without an accession 
record of any kind. The writers, however, have spent nearly two 
years in an effort to make the presentation the best possible within 
the limits of reasonable expenditure of time and effort. For many 
stations it is thought that complete accuracy has been attained. 
For others the \sTiters have done their best, but some uncertainty 
remains. 
Probably some errors have been introduced by averaging varieties 
thought to be identical. The number of individual-plat yields was 
so large that to make the work as useful and available as possible 
yields were averaged where supposedly identical varieties were 
included. 
From the standpoint of adaptation of barley types, minor errors 
and impurity of variety are not of dominant importance. There has 
been no attempt to make varietal recommendations from the results 
of the early experiments. Most of the barleys grown at that time 
were commercial varieties of what might be termed ecological races. 
Examples of these are Coast and Manchuria. Each of these con- 
tained a large number of biotypes which could be isolated as pure 
lines, but in each case these pure lines were adapted to the region of 
origin of the parent variety. These parent mixtures when grown for 
many years at a given experiment station in the United States under 
conditions which differed from those of the original habitat must 
alter decidedly in the proportions of the constituent strains. They 
must differ also from the resulting complex of the same mass variety 
grown at another station. They are comparable, however. The 
strains of each are similar, if not identical. They are as comparable 
with each other as vvith themselves from year to 3'ear. The 3'ields of 
these varjdng mixtures of unpurified stocks m^ust give a valuable 
indication of the types of barley adapted to the area where tested. 
At experiment stations there also is mechanical mixing of varieties. 
This was doubtless greater in the earlier years than at present. 
Equipment and assistance are now more adequate. This mixing of 
varieties probably has not affected the identification and value of 
the results as here used. If a variety became mixed to the extent 
of 10 per cent with another that yiekied only 80 per cent as much as 
the first, the yickl woukl be reduced only 2 per cent. This is much 
less than is held to be a sio:uificant difference in this digest of results. 
