86 W. C. Etheridge 
WORK OF PREVIOUS INVESTIGATORS 
Although there have been in this country no reports of extensive system- 
atic studies of varieties of oats, several methods of classification have 
been proposed by foreign investigators. These are found to differ widely 
in the arrangement of classes, and in the importance accorded various 
characters by which groups are distinguished and further separated into 
subgroups and varieties. Considerable space, therefore, is here devoted 
to outlining and discussing the previous systems of classification, in order 
to appraise them as means of identifying varieties as well as to show 
precedence for certain taxonomic features of the classification herein 
presented. 
The first noteworthy systematic study of cultivated oats was by Kor- 
nicke and Werner (1885). 2 In the classification by these authors, species 
are distinguished by adherence or non-adherence of the lemma and the 
palea to the caryopsis; by the number of awns produced by the spikelet; 
and by the toothing and color of the lemma. Within the species, various 
types are distinguished by the form of the panicle; by the color of the 
grains; and by presence or absence of awns and hairs of the lemma. The 
system of twenty-nine groups thus formed is here briefly outlined: 
Kernel closely invested by the hull (covered oats). 
I. Spikelets awnless or 1-awned. 
A. Panicle equilateral, spreading. 
a. Grains white. 
1. var. mutica Al. Grains white, lanceolate, awnless. 
2. var. praejravis Kr. Grains white, egg-shaped, awnless. 
3. var. aristata Kr. Spikelet 2-grained; grains white, awned. 
4. var. trisperma Schubl. Spikelet 3-grained; grains white, awned. 
b. Grains yellow. 
5. var. aurea Kcke. Grains yellow, awnless. 
6. var. Krausei Kcke. Grains yellow, awned. 
c. Grains gray. 
7. var. grisea Kcke. Grains gray, awnless. 
8. var. cinera Kcke. Grains gray, awned. 
d. Grains brown or red. 
9. var. brunnea Kcke. Grains brown, awnless, hairless. 
10. var. setosa Kcke. Grains brown, awnless, bristly. 
11. var. montana Al. Grains brown, awned, hairless. 
12. var. rubida Kr. Grains red, awned, hairless. 
e. Grains black. 
13. var. nigra Kr. Grains black, awnless. 
2 Dates in parenthesis refer to bibliography, page 163. 
