A Classification of the Varieties of Cultivated Oats 99 
lower grain from its peduncle, but these authors do not relate the form 
of the base with the more definite character of articulation or non-articu- 
lation. Bohmer (1911) also mentions several forms of grain bases, but 
does not use them in his classification. 
In the present study this character was found of the utmost value for 
distinguishing the cultivated forms of A. sterilis from those of A.fatua. 
The articulation of the lower grain is not so distinct as in the wild type, 
but the lines of separation may easily be recognized, and these, together 
with the adherence of the upper grains to their rhachillas, afford a reliable 
means of identifying A. sterilis forms. 
HAIRS OF THE GRAIN 
The hairs, or bristles, of the grain have been used by many systematists 
in the classification of cereal varieties. Neergaard (1889), in classifying 
varieties of barley, uses the hairs at the base of the grain as one of two 
fundamental variants for the distinction of groups. Other investigators, 
notably Blaringhem (1904) and Harlan (1914), have supported Neer- 
gaard's system. Broili (1906), however, believes the hairs would be 
inconstant under various environments, and hence not a reliable means 
of classification. Scofield (1903) includes the length and the color of 
hairs at the base of the glumes in his descriptions of wheat varieties. 
Fischer (1900) holds the appearance of hairs in oats as a mark of degen- 
eration, which is more frequently manifest in winter varieties than in 
others. In the classification and description of varieties of oats by Denaiffe 
and Sirodot (1901) and by Kornicke and Werner (1885), the hairs of 
the grain were employed as supplementary marks of distinction. The 
last-named authors, however, do not state the exact location of the hairs 
to which they refer, and hence their use of the character is somewhat 
vague. 
In the most precise use of the character as an aid in distinguishing 
varieties of oats, the hairs of the grain must be classified as (1) hairs of the 
lemma, (2) hairs of the callus, and (3) hairs of the rhachilla (Plate I, 
2, a and b). 
Hairs of the lemma 
The lemma (also called the flowering scale, flowering glume, inner 
glume, and superior glume) is the lower of two bracts immediately inclos- 
