696 
Cross-fertilisation of Cereals. 
There seems no reason to doubt that all our cultivated 
barleys belong to a single species. The spikelets of the ear are 
borne in groups of three, on the opposite sides of the axis, but 
in the usually cultivated varieties only the centre spikelet ot 
each group is perfect and produces seed. The ear is two-rowed, 
but each row has a barren flower on each side ; the two from 
the opposite groups of spikelets are placed close together along 
the centre of the flat face of the ear, hiding the axis (Fig. 4, 
Two-rowed Barley). This is Hordeum distichum (L.), including 
all the two-rowed forms, whether the ears are white or coloured, 
the glumes adherent or free from the grain (t.e. naked seeds). 
Sometimes the two lateral barren spikelets are fertile, while 
the central one is barren, and we have a four-rowed variety, 
which is the II. vulgare (L.). To this belongs the Himalayan 
barley, which has three short horns to the flowering glume, the 
central one being*broad, blunt, and curved over the grain. This 
is, no doubt, an inherited monstrosity, and often disappears under 
cultivation ; I have before me some ears in which a few of the 
flowering glumes terminate in the normal awn, while the others 
have the three short horns. 
Frequently all three spikelets are perfect, and a six-rowed 
ear is produced. To such plants the name II. hexastichon (L.) 
was given. This explanation of the different forms of cultivated 
barleys, if it be accepted, makes them merely varieties of a single 
species, and gives the reason for the ease with which cross- 
fertilisation has been carried out between them. 
In the hope of developing all the flowers in the spikelet, and 
still retaining the quality of seed of the best cultivated varieties, 
Messrs. Garton crossed the short-eared six-ranked Bere (fig. 4, 
No. 1) with the two-ranked Golden Melon (fig. 4, No. 4). This 
has, after further crossing, resulted in the composite varieties 
shown in fig. 4, Nos. 2 and 3; the one normally awned, the 
other with only rudimentary awns, both possessing grains equal 
in size and quality to those of the Golden Melon, but, being six- 
ranked, three times more numerous. 
There are three well-marked forms of oats to which the 
various cultivated varieties can be reduced : (1) The Common 
Oat ( Arena saliva , L.), which has an open panicle, spreading 
equally all round the axis, and spikelets with two thin barren 
glumes enclosing two or more flowers. The flowering glume 
generally adheres to the grain, but there are varieties with a 
naked seed, in which the flowering glume is thin and paper-like. 
(2) The Tartarian Oat ( A . orientalis , Schroeb.), in which the 
branches of the panicle lie to one side of the main axis : it has 
white and black-seeded varieties. (3) The Chinese, or Naked 
