A Classification of the Varieties of Cultivated Oats 95 
of types, but the identification of separate varieties by this system would 
be tedious, since it is left to the comparison of descriptions. 
2. Atterberg's method of bringing together varieties alike in physical 
properties offers merely a system for the determination of the quality 
of giains. Groups of varieties thus classified would lose their identity 
under radical changes of environment. The system fails to group varieties 
of the same morphological character, and therefore it cannot be used 
for their identification. 
3. The system proposed by Denaiffe and Sirodot is largely based on 
the relative forms of grains and their absolute measurements and weights, 
and it lacks efficiency to the extent of its employment of such characters. 
However, certain morphological characters suggested by these authors 
are useful both for identification and for description. 
4. Nilsson's classes, chiefly described by the form of panicles, are often 
transitional and lacking in distinctiveness; and hence the group relation- 
ship of varieties would often be extremely difficult to determine by this 
system. 
5. Bohmer's system combines the panicle classes of Nilsson with certain 
grain forms described by Atterberg. Classes arranged by this system 
would therefore be both transitional and subject to radical changes by 
the influence of environment. 
GENERAL CONSIDERATIONS 
To be of practical use, a classification of any group of economic plants 
must serve a twofold purpose: it must provide a means of identifying the 
members of the group, and it must standardize varietal nomenclature. 
The previous systems of classifying varieties of oats do not fulfill this 
purpose. Each of them fails as a means of identifying large numbers of 
varieties, for one or more of the following reasons: (1) a physical basis of 
construction; (2) a lack of competent and stable distinctions for groups 
of varieties; (3) a lack of systematic differentiation of groups into individual 
varieties. As a means of establishing a system of varietal nomenclature 
these earlier classifications, all of them foreign, are of little use in this 
country. American and European varieties of similar form are gen- 
erally differently named, and hence much confusion would attend the 
adoption in this country of a European standard of nomenclature. 
