TYPE 2. GRAINS SIMPLE, CENTRIC, LENTICULAR. 203 



Polygonum oricntale Linn. {Polygonacecc.) Fresh seed. Grains spherical, or somewhat angul.T,r 

 owing to pressure; hihim usually distinct. Size about lOyu. Croups of adhering grains 

 and also compound grains occur, the latter not easily distinguished from the former. Some 

 semicompound forms with several hila were also observed. 



Fagopyrum cymosum Meisn. {Polygonacecc.) Fresh seed. Grains spherical or oval-spherical, usu- 

 ally more or less polyhedral owing to pressure; no lamella;; the larger grains with a distinct 

 central hilum; when dry, with a cavity, not often with radial fissures. Size of the spherical 

 about 17/i and that of the oval about 2lfi. 



Fagopyrum esculentum Moench.; Polygonum fagopyrum Linn. (Polygonacece.) Dry seed. Grains 

 spherical or oval, frequently more or less angular or even polyhedral owing to pressure; 

 with small central cavity from which, at times, single short fissures radiate. Size about 10 

 to 12/i. Among them compound grains with few part-grains in one or two rows. 



Emex spijiosa Cambess. {Polygonacew). Dry seed. Grains spherical, or angular with rounded 

 corners owing to pressure; the larger ones with a small central cavity from which frequently 

 delicate fissures reach the surface. Size about 8n, rarely lOyu. 



Rumex ratientia Linn. (Polygonacew.) Dry seed. Grains spherical, or more or less slightly angular 

 owing to pressure; usually with large cavity. Size about 12 to 14;u. 



Tragopyrum lanceolatum Biclirst. (Polygonacece.) Dry seed. Grains rounded, almost angular, 

 occasionally with small central cavity. Size about Oyu. 



Airaphaxis spinosa Linn. (Polygonacece.) Dry seed. Grains spherical, frequently more or less angu- 

 lar owing to pressure; with small central cavity. Size about 6 to S/x. 



Antigonon species from Guatemala. (Polygonacece.) Dry seed. Grains spherical, rarely oval, usually 

 more or less polyhedral owing to pressure; some with small central eavit}^ and single short 

 radial fissures. Size about 13 to llfx. Among them comjjound grains consisting of 3 to 5 

 part-grains disposed in rows. 



Pisonia aculeata Linn. (Nyctaginiacece.) Dry seed. Grains spherical or polyhedral, frequently 

 with one curved and several pressure facets; the larger with a central cavity, and at times 

 with several short radial fissures. Size about 13/u. Lhidoubtedly simple grains. A few 

 compound grains composed of 2 to more than 12 part-grains are present. 



Nepenthes destillatoria Linn. (Nepenthaceae.) Dry seed. Grains spherical, or with rounded corners to 

 almost polyhedral; with a large or small central cavity, and often with radial fissures. Size 

 10 to 13m. 



Acanthus mollis Linn. (Acanthacece.) Fresh and dry cotyledons. Grains spherical to oval, not at 

 all or slightly compressed; with delicate, indistinct lamellse; fresh, with central spherical 

 hilum; dry, with marked radial fissures, which extend almost to the periphery, the fissures 

 being equallj' marked in all aspects. Size about 60^. Among them are semicompound and 

 compound grains with few equal or unequal size part-grains due to the splitting of the hilum 

 as well as to the breaking away of corners. The starch-grains and cell-tissue of Acanthus, 

 like the seeds, resemble tlie starchy seeds of the Papilionacew. 



Drosera longifolia Linn. (Droseraceas.) Dry seed. Grains spherical or oval-spherical, rarely oval, 

 many of them more or less polyhedral owing to pressure; with a central cavity and several 

 marked radial fissures, some of which frequently are short, others extend to the periphery, 

 and appear to split the simple grain into part-grains. Size about 18/j. In unripe seeds 

 rounded grains only occur, while in the ripe seeds many polyhedral grains are seen along 

 with them. 



Drosophyllum lusitanicum Spreng. (Droseracece.) Dry seed. Grains spherical or nearly oval, but 

 rarely oval, and many of them more or less polyhedral owing to pressure; with small central 

 cavity and radial fissures. Size about 15 to 19^. 



Type 2. Grains Simple, Centric, Lenticular. 



Grains circular, rounded-oval, kidney-shaped, or triangular, or 3 to 4 angular with rounded 

 corners and pres.sure facets; more or less polyhedral when crowded. Hilum in the center, usually 

 shaped like the grain, but much thinner in comparison. Lamellae usually of equal thickness at points 

 opposite to hilum, but thickest toward the margin of the grain. 



During the process of drying a fissure coinciding with the largest plane is nearly always formed, 

 and from which radial fissures issue, which are usually invisible on the broad aspect but appear as 



