A Classification of the Varieties of Cultivated Oats 111 
and any distinction by this character must be 
according only to the 
prevailing number of 
grains. In all previous 
classifications the pre- 
vailing number of grains 
in the spikelet has been 
given greater or less 
prominence in the 
characterization of 
groups. Atterberg 
(1891) distinguished 
three main groups of 
his system by this 
means. Other investi- 
gators, however, have 
made less use of the 
character, employing 
it as a supplementary 
distinction or only in 
special cases. 
The chief objection to 
the use in classification 
of the number of grains 
in the spikelet is because 
of the uncertain defi- 
nition of one-, two-, or 
three-grained spikelet s. 
Shall the definition be 
based on the number of 
fully developed grains, 
or shall it include de- 
fective grains? Thus 
there is no definite point 
at which fully devel- 
oped two-grained spike- 
lets can be separated as 
a class from those of the defective double-grained 
\ 
Fig. 13. panicle of avena 
sativa orientalis, show- 
ING PECTINATE 
OF SPIKE LET'S 
ATTITUDE 
(A 
Fig. 14. panicle of avena 
sativa orientalis, show- 
ing confused attitude of 
spikelets 
