TYPE ]. GRAINS SIMPLE, CENTRIC, SPHERICAL. 199 



rather diminutive sizo, they may be undeveloped forms of an eccentric type, and the fact that 

 eccentric grains are found in related plants makes the likelihood probable. They are therefore 

 classified as grains of indefinite structure. Single compound grains are often found along with 

 centric, spherical ones, their components being arranged either spherically or lineally. 



Pharus scaber Humb., Bonp. (Graminacece.) Dry seed.— Grains rounded-angular to jiolyhedral, 

 with small central cavity and several radial fissures. Size about 2^^^J.. 



Zea mays Linn. {Graminacece.) Fresh seed. — Grains during early development at first spherical, 

 seldom oval, most of them being twice as long as broad; later, mostly polyhedral with sharp 

 edges; hilum distinct, very rarely with delicate lamella surrounding it. Size about IG to 21/i. 

 The dried grain usually has a central cavity with radial fissures. In the fresh, not fully 

 developed grains several short radial fissures also occur, as well as grains with granular outer 

 surfaces. Irregular compound grains of 2 to 6 part-grains are often found among the simple 

 ones. The grains in the outer part of the seed are somewhat smaller (about IG/z) than in 

 the inner part (about 21^). According to Payen (Ann. So. Nat., 1838, ii, p. 23), the starch- 

 grains of maize average 30,u and the horn-like part of the seed contains crowded polyhedral 

 grains, while the inner mealy parts inclose more rounded, loosely arranged ones. 



Coix lacryma Linn. {Graminacece.) Dry seed.— Grains spherical, frequently more or less angular 

 owing to pressure; no lamellae; solid or with a small central cavity having sometimes numer- 

 ous fissures radiating from it. Size about 12 to 16/i. 



Paspalum dilatatum Poir. {Graminacece.) Dry seed. — Grains rounded or oval, many of them angu- 

 lar or polyhedral owing to pressure; no lamella; sometimes with small central cavity. Size 

 about G to 7n. 



Paspalum platycaide Poir; P. complanatum Nees. {Graminacece.) Dry seed. — Grains as in P. dila- 

 tatum, the larger ones with central cavity from which several short fissures radiate. Size 

 about 8n, rarely up to 12/i. 



Paspalum stoloniferum Bosc; Maizilla stolonijerum Schlecht. {Graminacece.) Dry seed. — Grains 

 angular with rounded corners to polyhedral, with sharp edges and angles; the larger ones 

 with a central cavity from which short fissures sometimes radiate. Size aljout 12/x. The grains 

 which have fallen out of the cell are often clumped together, resembling compound grains. 



Amphicarpum purshii Kunth. {Graminacece.) Dry seed. — Grains spherical to almost polyhedral; 

 no lamella; the nuijority with single short fissures radiating from the center. Size about lO/n. 



Olyra paniculata Swartz. {Graminacece.) Dry seed. — Grains polyhedral, filling the cells; the larger ones 

 mostly with a large or a small cavity, and rarely with single, delicate fissures. Size about 12ju. 



Oplismenus colonus Humb., Kunth.; Panicum colonum Linn. {Graminacece.) Dry seed. — Grains 

 rounded, sometimes angular owing to pressure, with small central cavity from which fissures 

 radiate. Size about lO/x. 



Oplismenus frumentaceus Kunth.; Panicum frumentaceum Roxb. {Graminacece.) Dry seed. — Graiios 

 spherical or oval-spherical, sometimes angular owing to pressure; the largest ones some- 

 times somewhat shrunken; with a central cavity, rarely with short radiating fissures. Size 

 about 14 to 18/i. 



Selaria glauca Brauv.; Panicum glaucum Linn. {Graminacece.) Dry seed. — Grains spherical or oval- 

 spherical, often angular owing to pressure; often with small central cavity, with radiating 

 fissure; sometimes appears to be split into several part-grains by these fissures. Size about 

 8/i. Single grains with granular surfaces. 



Setaria italica Beauv.; Panicum italica Linn. {Graminacece.) Dry seed. — Grains during early ilevel- 

 opment spherical or oval-spherical, but later polyhedral with sharp edges; no lamella; 

 often with distinct central hilum. Size about 14/u; according to Payen sometimes 16/i. Fre- 

 quently some of the grains have granular surfaces, probably the result of abnormal solution. 

 Compound grains of 2 to 3 part-grains appear with the single ones; these can best be observed 

 in not fully developed seeds. 



Selaria flava Kunth; Panicum alopecuroideum Schreb. {Graminacece.) Dry seed. — Grains as above; 

 increasing in size from the sm'face to the middle of the endosperm. 



Isachne australis R. Br.; Panicum anlipodum Spreng. {Graminacece.) Dry seed. — Grains angular 

 with roundish corners to polyhedral (filling the cells); the larger ones usually with central 

 cavity and frequently with radial fissures. Size about 13yu. 



