. Bulletin of the Department of Agriculture. Agriculture; Agriculture. MORPHOLOGY OF THE BAELEY GRAIN. aJly proceeds from the glumes inward. The glumes, the seed coat of the caryopsis, and the seed proper, each consists of several kinds of tissue. THE GLUMES. The outer surface of the glume is protected by a heavy cuticle. The cuticularization does not penetrate deeper than the first row of cells. The three outer layers of cells have heavily reinforced (scler- enchymal) walls, while the underlying layers are thin walled and more variable. They are usually three or four in number. The vascu
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. MORPHOLOGY OF THE BAELEY GRAIN. aJly proceeds from the glumes inward. The glumes, the seed coat of the caryopsis, and the seed proper, each consists of several kinds of tissue. THE GLUMES. The outer surface of the glume is protected by a heavy cuticle. The cuticularization does not penetrate deeper than the first row of cells. The three outer layers of cells have heavily reinforced (scler- enchymal) walls, while the underlying layers are thin walled and more variable. They are usually three or four in number. The vascular bundles of the glume are normal leaf bundles THE SEED COAT OF THE CARYOPSIS. The term ''seed coat of the caryopsis" is here used to include groups of tissues from three separate origins: The pericarp, the testa, and the semipermeable membrane. The pericarp is the remains of the ovary waU. Its outer layer hes flat against the glume and is united with it. Beneath the layer in contact with the glume are several layers of parenchyma, consisting of much flattened and often almost dis- connected cells. Below this arc two layers of parenchyma that formerly contained chlorophyll. Though equally flattened through pressure, they arc in much better condition as a layer. The cells of this tissue are abnost at riglil angles to those of the main pa- renchyma region and tangential to the grain. On the inside of the pericarp are sometimes found scattering fragments of the inner epidermis of the ovary, their cells also elongated lengthwise with the grain. The testa is the remnant of the inner of the two integuments that once existed inside the ovary wall, tlui outer one ha\dng disa])pear(l. The cells of the testa are crushed almost to the point of disa])])earance, being repr(^s(!nte(i in the rijx'ned grain })y a Jiiereline. In intiinat(MU)n- tact with the testa and much better preserved is the inv(!sting mem- brane of the nucellus. It consists of moderately thickened ('(dlsflatlcned by
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