TYPE 1(5. GRAINS COMPOUND, MANY COMPONENTS. 273 



Cereus variabilis Pfeiff. (Cactaccw.) Fresh pilh of the stem. — Coinpoiiiul gruins roundetl or o\'al 

 u;<u;ill>- irrcfiiular, consisting of 2 to 12 unci 20 components which are ahnost always unequal. 

 .Size 40 to 60m. Separatcd-grains, size 4 to 30 and .50^; the larger ones with eccentric and 

 frequently irregular lamella'. Occasionally semi-compound forms with 2 or moi-e inclosed 

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

 present. 



Malva borealis Wallmann. (Malvacece.) Dry root. — Compound gi-ains consisting of 2 to 4 and 8 

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

 arated-grains, size 3 to Oju; 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. {Malvacew.) Dry root. — Compound grains consisting of 2 to 10, rarely 

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

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

 also single short radial fissures. 



Circaa 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 

 h-regularly arranged; size about 24yu. Separated-grains, size 3 to lOyu; the larger ones have a 

 small cavity instead of the hilum; eccentricity about one-half. 



Spiraea filipendula Linn. (Rosacece.) Dry roots. — Compound grains rounded 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 16/x, separated-grains; size 2 to 12ju; the larger ones with a small cavity. 

 Simple grains of incomplete formation are also present. 



Orohus albus Linn. {Leguminosw.) Dry thickened roots. — Compound grains consisting of 2 to 4 anrl 

 G mostly unequal components; size about IG/x. Separated-gi'ains, size 3 to 12fi; 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 mariiima Linn. {Naiadacece.) 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, 

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

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

 grains, probably centric-oval, are also present. 



Quercus pedunculata Ekrh. {Cupulifcra!.) Fresh cotyledons. — Comjioimd grains consisting of 2 to 3 

 and 4 components which are sometimes regidar, though more often irregulai-, comjionents. 

 Sejiaratcnl-grains isodiametric or oval; occasionally with a distinct ccuitral liilmn; size about 

 l()/i. Simi)lo grains of incomplete formation are also present. 



Casliinospermum australe Cuim. iCupiliferoc.) Dry cotxjledons. — Compound grains spherical or oval, 

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

 Separated-grains; size 3 to 15^; with one curved surface and 1 to 5 jiressure facets; the larger 

 ones have a small cavity, and single fissures extending to the sm-face of the pressure facets. 



Type 16. Grains Compound, Many Components. 



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

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

 are outlined 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 with other tyi^es, 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 gi-ains. Sometimes 

 transitions between types 16 and 14 occur, making it doubtful 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 fissm-es, the two, however, do not always occur in like proportion. If the separating 

 lines decrease in width more rapidly than the comjionents, the grain appears netted or delicatelj' 

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

 the whole grain appears granulated, and if they arc smaller than Iju it looks homogeneous. In both 

 cases the fact that the starch-grains are compound can be recogiiized only after they have fallen 

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



18 



