. Carnegie Institution of Washington publication. 804 STARCHES OF CANNACEiE. P IGV T P S Chart No. 340. GV S T CI CA PA FC PS CI PA CA STARCH OF CANNA VAR. (PRESIDENT CARNOT). (Plate 84, figa. 501 and 502. Chart 340.) Histological Characteristics.—In form the grains are simple, except rare compound grains con- sisting of two components. There are no aggregates, clumps, or pressure facets. The surface shows a marked tendency to irregularity, owing in part to a curving of the grains, but chiefly to rounded protuberances and nipple-like projections. The conspicuous forms are flattened, irregular
. Carnegie Institution of Washington publication. 804 STARCHES OF CANNACEiE. P IGV T P S Chart No. 340. GV S T CI CA PA FC PS CI PA CA STARCH OF CANNA VAR. (PRESIDENT CARNOT). (Plate 84, figa. 501 and 502. Chart 340.) Histological Characteristics.—In form the grains are simple, except rare compound grains con- sisting of two components. There are no aggregates, clumps, or pressure facets. The surface shows a marked tendency to irregularity, owing in part to a curving of the grains, but chiefly to rounded protuberances and nipple-like projections. The conspicuous forms are flattened, irregular ovoid, also broad ovoid, oval, pointed oval, flattened oval, irregularly quadrilateral, pyriform, bent or straight lenticular, triangular with rounded angles, clam-shell type and mussel-shell type. The grains are flattened and from one-fourth to one-half as thick as they are broad, and about one-half to three-fourths or more as broad as long. The hilimi is sometimes invisible, owing to its extreme eccentricity; when not so eccentric, it appears as a small, distinct, round or rarely elliptical spot, which may be located as far inward as one-sixth to one-ninth of the longitudinal axis, and in or to one side of the median line. There are occasionally 2 hila, and rarely more than 2 maj' be present and arranged linearly. The hila may or may not be sepa- rated from one another by a depression or a fine fissure, but the hilum itself is never fissured. The lanwllce are very distinct, fine, regular or irregu- lar circles, or arcs of circles which are probably continu- ous. Except those immediately surrounding the hilum, they tend to follow the outline of the distal end, but are often wavy and otherwise irregular. They are frequently arranged so that bands of varying numbers of fine lamellae are grouped by scattered large, coarse lamellae. The lamellae vary somewhat in size and distinctness in the different grains and also in the same grain, being usually not so fine but more distinct
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