24 r BULLETIN 137, U. S. DEPAEIMEXI OF AGEICULTLEE. 
Aside from the observations upon established forms, it has been 
the fortune of the writer to isolate a number of which there seem 
to be no published descriptions. These all came from Abyssinian 
barleys, and. as the work is not yet completed, only a general indi- 
cation of the results need be given here. The group of 2-rowed 
barleys with rudimentary florets seems much larger than has been 
previously thought. They vary from the wide zeocrithonlike types 
to narrow nutanslike forms and through a series of colors and com- 
binations of colors. In barleys received from the same region there 
is a group with a curious irregular, yet heritable, habit of floret 
abortion. In the ripened spike the spikelets are normal at the base 
and for a varying distance toward the tip. The upper portion 
usually reduces suddenly to a 2-rowed form. In this case the lateral 
spikelets are not merely sterile, but are reduced to only the outer 
glumes and the rachilla, the floret having disappeared entirely. The 
spikes are found to present these modifications even when the head 
first emerges from the boot. The actual time of the reduction has 
not been determined, but it is so early that no scar is present, indi- 
cating that the floret never started to develop. 
THE EMPTY, OR OUTER, GLUMES. 
The outer glumes present but two phases. They are usually nar- 
rowly lanceolate, but in rare forms are ovate lanceolate. In the 
latter case they generally bear moderately long awns. A few inter- 
mediates are formed by combinations in which only certain ones 
instead of all the normal outer glumes are replaced by ovate-lanceo- 
late ones. In this investigation, while numerous ovate-lanceolate 
selections have been made, there has been nothing added to the 
information already at hand. 
THE FLOWERING GLUMES. 
Two of the variable features of the flowering glume are treated 
elsewhere. The toothing of the nerves is considered with the rest 
of the Svalof system under a later heading. The color of the giumes 
is taken up with the color of the other plant organs in the general 
discussion of pigmentation. Most of the remaining variable points 
of structure in the flowering glume are to be foimd in its terminal 
appendages, which are usually awns, but may be trifurcate hoods, 
in the nature of its base, and in its adherence or nonadherence to the 
pericarp. 
AWNS. 
The dimensions of the awns are naturally their most apparent- 
variable features. There are marked varietal differences in both 
length and breadth of awns, but, unfortunately, they are so corre- 
