THE IDENTIFICATION OF VARIETIES OF BARLEY. 9 
of the problem to be solved. When it is realized that a great number 
of these forms are known and that there is no reason why all of them 
can not be produced, or indeed may not be found already in exist- 
ence in some part of the world, the futility of continuing the policy 
of describing each minor variation becomes apparent. In fact, there 
is more to be done than merely resolving not to add to the confusion. 
Over 200 forms have been named and described. Some semblance 
of order must be brought about in the work already published and 
some constructive plan suggested whereby future additions may be 
limited to variations of real importance. "When the variable char- 
acters are studied carefully with this object in view, it soon becomes 
apparent that the factors are not all of the same value. 
The fertility and the adherence or nonadherence of the lemmas are 
major distinctions. They seldom present any difficulties. The 
nature of the appendages of the flowering glume are major distinc- 
tions so far as the distinctions between awns and hoods are con- 
cerned. The presence or absence of hoods is obvious. In the sepa- 
ration of varieties the term " awned " has been made to include awn- 
less and all intergradations, as a complete series from awnless to fully 
awned seems likely to exist. White and black kernels are also major 
distinctions. White has been used to include blue and purple, because 
of the frequently imperfect production of the latter pigments and the 
difficulty of determining doubtful varieties. By using only these 
four groups, the varieties are founded upon distinct and readily sepa- 
rable characters. Each variety is then a specific, tangible group. 
As lesser but still usable distinctions there are the awnless and 
smooth-awned variations of the awned form, the blue and purple 
variations of white, and the character of the outer glumes. 
Besides these, a considerable number of characters have been used 
in establishing varieties which in the light of present information 
seem unsuited as bases for taxonomic groups. In many instances 
they are very useful in agronomic work in the description of biotypes 
and in the identification of farm varieties, but they are not here recog- 
nized. Varieties which have been established upon these characters 
will be found only in the alphabetical list of rejected forms. These 
characters will not be discussed individually, but will be found 
listed in the summary below. 
To summarize the variations, the three grades of distinction are as 
follows : 
Major distincUo-ns useful in estahlisMng species and varieties: 
Spikes 6-rowed, intermediate. 2-rowed, and deficient. 
Kernels hulled and naked. 
Lemmas awned (including awnless) and hooded. 
Kernels white -(including blue and purple) and black. 
14681°— 18— Bull. 622 2 
