220 Trans. Acad. Sci. of St. Louis. 



dosperm.— ix, Hordeum vidgare: thick-walled cells of glume with pore 

 canals; alcurone cells of more than one row. 



Plate XIX. — i, Cenchrus tribuloides: aleurone layer of a single row of 

 cells; starch grains spherical or elliptical. — n, Panicum Crus-galli: glume 

 adjacent to pericarp with lower layer of cells thick -walled, showing pore 

 canals; single row of cells to aleurone layer; starch grains solidly packed. — 

 ill, Festuca Shortii: aleurone layer of one or more rows, cells of the nucellus 

 thick-walled ; starch grains apparently compound, showing individual com- 

 ponent parts separated. — iv, Sorghum vulgare var. communis (Andropogon 

 Sorghum var.) : small aleurone cells ; simple spherical or elliptical starch 

 grains. — v, Bouteloua hirsula: aleurone layer of several rows of cells; 

 starch grains solidly packed. — vi, Avena sativa: pericarp with irregular 

 cells on surface; the minute down of " seed; " Aa single row of cells to 

 aleurone layer; in B more than one row; starch grains compound. — 

 vn, Sporobolus cryptandrus : pericarp, c, mucilaginous; aleurone cells small, 

 of a siDgle row; U, a more magnified portion of the pericarp and testa after 

 the addition of chloral hydrate. — vin, Phragmites communis : aleurone layer 

 of a single row of cells, starch grains solidly packed. — ix, Triticum vulgare: 

 aleurone layer a single row of cells, cell-walls of testa and pericarp thick- 

 walled; longitudinal view of pericarp cells shown at b; starch grains large, 

 spherical. — x, Koeleria sp. : nucellus a single row of cells, also the aleurone 

 layer; starch grains large, compound, testa of a single row of cells. — xi, Zea 

 Mays: nucellus a single row of cells; pericarp much more developed than 

 testa. 



Issued December 29, 1898. 



