96 A GRAIN OF BARLEY. 
ence of pollen. The flowers of the grasses, however, do not 
require the aid of insects for fertilization, the pollen being 
transferred from flower to flower by the wind, or the flower 
being self-fertilized ; hence the necessity of attracting insects is 
not important, and we consequently find the floral envelopes 
existing in the lodicules in an inconspicuous form which we 
must look upon either as rudimentary or vestigial. 
Long-continued observations and experiments have convinced 
botanists that the transference of pollen from the anthers of 
one flower to the pistil of another of the same species results 
in the production of plants which are more vigorous, and better 
fitted for the struggle for existence, than those produced by 
the self-fertilization of a flower by its own pollen. We find, 
almost everywhere, most wonderful contrivances for ensuring 
cross-fertilization and for preventing self-fertilization. Sometimes 
the male and female flowers grow on different individual 
plants, at others the structure of the flower is such as to 
render self-fertilization difficult or even impossible, whilst 
again, the male and female portions of the same flower arrive 
at maturity at different times. Almost everywhere in the 
vegetable kingdom there is overwhelming evidence of the 
truth of Darwin’s doctrine that ‘Nature abhors perpetual 
self-fertilization,” and it is consequently with some surprise 
that we find in the barley-plant an apparent exception to this 
principle. The pistils and stamens of barley are so closely 
invested by the overlapping glumes or palez that, at first 
sight it would scarcely appear possible that any transference 
of pollen could take place from flower to flower, as is mani- 
festly so frequently the case in most of the other cereals. In 
the ordinary two-rowed barley self-fertilization is unquestion- 
ably the rule, but we find, even in this variety, that a few of 
the flowers occasionally expand for a very short time in the 
early morning, and allow the ripe anthers to protrude and 
scatter their pollen. This pollen is disseminated by the wind, 
and, in my opinion, its access to the pistils of the other 
flowers is much facilitated by the swaying of the awn or beard 
