418 Form of Seeds as a Factor [July, © 
rapidly than in others, through the conquering advance of another 
plant, a form which, being not only worthless as food but repug- 
nant to cattle, is not molested by them in its onward march for 
supremacy, which over large areas it has already achieved, to the 
nearly total exclusion of Erodium. 
This latter is what is known as barley-grass, or false barley, 
Hordeum maritimum, of which a spikelet is shown in the follow- 
ing figure (8). 
b 
Fic. 8. Spikelet of Darley Grass. 
Upon a careful examination it will be seen that the entire 
spikelet throughout is closely set either with short rigid bristles 
(as on the glumes and palea) or with minute sharply-pointed 
barbs as exhibited in the awns throughout their entire length, and 
on the edges of the arrow-shaped base or stem (insertion point) 
of the spikelet. Upon the long bristle-like awns these barbs are 
closely set, but are so very small as not to be at first detected ; 
on pulling one of them through the fingers in a direction from 
the tip æ towards the extremity of the awn. 4, no difficulty is 
encountered, it may be done with ease; but on pulling it in the 
opposite direction, namely, from 4 towards a, resistance ensues 
from the multitude of minute barbs, and the effort, if pensinto in, 
. results i in 1 the ER of the awn. 
