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1. In some species, as in the sweet-vernal grass, (Anthoranthum,) the 
stigmas are thrust ont of the fiower some time in advance of its own 
stamens, and are fertilized by pollen from earlier developed flowers. A 
similar arrangement exists in the meadow-foxtail (Alopecurus) and many 
other grasses. In these cases there is usually only a short period during 
which the pistil remains fresh and capable of fertilization; in Phalaris 
arundinacea, however, Professor Hildebrand found the stigmas fresh and 
receptive for a longer time. 
2. In by far the larger number of grasses the male and female organs 
mature at the same time in the same flower; but even here there are 
circumstances which in some species seem favorable to self-fertilization, 
and in others to cross-fertilization. Thus, in rye, the anthers are partly 
extended beyond the points of the inclosing chaff, before the full expan- 
sion of the flower, so that the pollen first shed goes to the fertilization 
of other flowers which are already open. When the flower fully expands, 
and the rest of the pollen is shed, only a portion is likely to fall upon the 
stigmas of the same flower owing to the relative position of the parts, the 
ereater portion being conveyed to other flowers. In the common oat 
(Avena sativa) the flowers, in dry weather, open in the afternoon and 
toward evening. The anthers hang out of the flower, and the pollen is, 
to by far the greater extent, dispersed to other flowers; but in damp 
and cold weather the flowers remain closed, the pollen is shed within the 
flower, and self-fertilization is inevitable. The flowers of rice (Oryza 
sativa) open in the morning, and the arrangement is nearly the same 
as in the oat, favorable to cross-fertilization. 
In all the observations made by Professor Hildebrand on different 
species of barley, no flowers were found to be open, but all were self- 
fertilized, even before the spike or head was protruded from its sheath. 
However, another observer, Delphino, asserts that there is at least the 
possibility of cross-fertilization in barley. He states that the spike of 
Hordeum vulgare has six rows of flowers, and that the flowers of the 
two middle rows never open, and are, therefore, subject exclusively to 
self-fertilization, while the flowers of the other four rows open slightly 
and disperse a portion of their pollen in the air. In Hordeum distichum 
the flowers are also in six rows, but only those of the two middle rows 
are perfect and fertile, while those of the other four rows are imperfect, 
containing stamens only. The fertile flowers never open, and are fertil- 
ized, while the spike still remains buried in its sheath. When first pro- 
truded the stigmas are already dead, thus showing the highest degree 
of self-fertilization. There are, however, he asserts, among these fertile 
flowers a very few which are destined for cross-fertilization; these re- 
main five or more days longer unpollenized than the rest, and they open 
slightly, so as to allow the entry of foreign pollen, especially from the 
male flowers. 
With respect to wheat, Delpino asserts that the idea that wheat is 
necessarily self-fertilized has arisen erroneously, from the fact that the 
flowers remain open only for a very brief time. In a wheat-field only 
a very small proportion, perhaps one in 400 of the flowers, are open at 
one and the same time. The opening of the flower of wheat is a very 
interesting phenomenon, and happens with wonderful rapidity. While 
the flowers are still closed, a motion of the glumes is observable; these 
separate suddenly in a moment; at the same time the anthers protrude 
laterally from the opening; they open and about one-third of the pollen 
falls inside the flower upon its own stigma, while the remaining two- 
thirds are dispersed into the air; the anthers are emptied in a moment, 
and the whole process does not occupy more than half a minute. The 
