TYPE 10. GRAINS COMPOUND, MANY COMPONENTS. 273 



Cereus variabilis Pfeiff. {Cactacem.) Fresh pith of the stem. Compound grains rounded or oval, 

 usually irrcpdar, consistins of 2 to 12 and 20 components which are almost always unequal. 

 Size 40 to (iOyu. Sc^paratcd-grains, size 4 to 30 and 50ju; the larger ones with eccentric and 

 frequently irregidar lamellte. Occasionally semi-compound forms with 2 or more inclosed 

 components are observed. Simple grains, as in type 10 of incomplete formation arc also 

 present. 



Malva borealis Wallmaim. (Malvacece.) Dry root. Comjiound grains consisting of 2 to 4 and 8 

 components which arc sometimes equal, though more often unequal; size about 13yu. Sep- 

 aratetl-grains, size 3 to 9fi; the larger ones have a small cavity, and occasionally also several 

 very short, radial fissures. Simple grains spherical and rounded-oval are observed. Starch 

 not very plentiful. 



Gossypium indicum Linn. {Malvacece.) Dry root. Compound grains consisting of 2 to 10, rarely 

 to more than 20, components which are equal, though more frequently unequal; size about 

 24/i. Separated-grains, size 3 to 16yu; the larger ones have a small cavity, and occasionally 

 also single short radial fiss\u-es. 



Circcea lutetiana Linn. (Onagracece.) Dry stolons. Compound grains round to oblong, frequently 

 irregular, consisting of 2 to 12 components, which are either equal or unequal, and usually 

 irregularly arranged; size about 24yu. Separated-grains, size 3 to 10^; the larger ones have a 

 small ca\'ity instead of the hilum; eccentricity about one-half. 



Spirwa filipendiila Linn. (Rosacea;.) Dry roots. Compoimd grains roimded to elongated spindle- 

 shaped, most of them more or less irregular, consisting of 2 to 8 and 12 equal or unequal com- 

 ponents; size about 16ai, separated-grains; size 2 to 12/i; the larger ones with a small cavity. 

 Simple grains of incomplete formation are also present. 



Orobus albus Linn. (Leguminosw.) Dry thickened roots. Compound grains consisting of 2 to 4 and 

 6 mostly unequal components; size about KV- Separated-grains, size 3 to 12;u; isodiametric 

 or oval; frequently they have a small cavity instead of a hilum, which in the larger oval 

 forms is about one-third eccentric. Simple eccentric-conical grains are also present. 



Ruppia maritima Linn. (Naiadaceoe.) Dry seeds. Compound grains consisting of 2 to 3, rarely 

 4 to 5, components which are occasionally equal though usually unequal (in the latter case, 

 I to 2 small components are attached to a large one). Separated-grains have central, fre- 

 quently irregular, cavity from which radial or irregidar fissures diverge; size about 21ij.. Simple 

 grains, probably centric-oval, are also present. 



Quercus pedunculata Ekrh. {Cvpidiferw.) Fresh cotyledons. Compound gi'ains consisting of 2 to 3 

 and 4 comi)onents which are sometimes regular, though more often irregular, components. 

 Separated-gi-ains isodiametric or oval; occasionally with a distinct central hilum; size about 

 IRyu. Simple grains of incomplete formation are also present. 



Castanospermum australe C\mn. {Cupiliferce.) Dry cotyledons. Compound grains spherical or oval, 

 consisting of 2 to 8, rarely^ more, usually unequal components. Size about 20 to 25/^. 

 Separated-grains; size 3 to 15/^; with one curved surface and I to 5 pressure facets; the larger 

 ones have a small cavity, and single fissm^es extending to the sm^face of the pressure facets. 



Type 16. Grains Compound, Many Components. 



From 20 to many thousand components united into a compoimd grain separated by slits 

 (sometimes almost invisible), and at full maturity falling away into separated-grains, most of which 

 are outUned on all sides by flattened pressure facets. These compound grains probably arise from 

 repeated division, and usually consist of almost equal or exactly equal components. Occasionally 

 they are not associated mth other types, but often are found either with isolated grains of few and 

 equal components (which belong to type 14), or very rarely with a few simple grains. Sometimes 

 transitions between types 16 and 14 occur, making it cloul:)tful to which group such grains belong. 

 As the components increase in number there is usually a decrease in their size and in the width of 

 the separating fissures, the two, however, do not always occur in like proportion. If the separating 

 lines decrease in width more rapidly than the components, the grain appears netted or delicatelj- 

 reticulated, but if the components decrease in size until they have become about l/x in diameter, 

 the whole grain appears granulated, and if they are smaller than l/z it looks homogeneous. In both 

 cases the fact that the starch-grains are compoimd can be recognized only after they^ have fallen 

 apart. Occasionally at certain stages in the development of an organ, for example in ripening seeds, 



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