ILLUSTRA TIONS OF MA IZE. 



ILLUSTRATIONS OF MAIZE. 



Fig. 286. Germination of Maize in successive stages. A and B, front and side views of embryo 

 separatelj^. In all parts of the figure w is tlie primary root ; ws. the root-sheatli : ?c', «•" . 

 secondary roots ; e, endosperm portion of seed ; .st, cotj'ledon : r. open edges of same ; k. the 

 plumule; b. 1/ , h" . young leaves ; /, part of the cast-off pericarp. (Sachs.) 



Fig. 287. Longitudinal section of a grain of Maize, c, adherent pericarp ; fs, base of fruit ; ey, 

 hard j^ellowish part of endosperm ; ew, soft white part of endosperm ; sc, cotyledon ; ss, its 

 apex ; e, its epidermis ; k, plumule ; iv (belowj, main root ; w (above), secondary roots arising 

 from the stem .st ; us, root-sheath (the line connected with these letters'should be longer). (Sachs. ) 



Fig. 288. Longitudinal section through apex of root of Maize. (A little more than lialf the width 

 of the root is shown.) All within the line vs is the root proper; all below and outside this 

 line is root-cap ; s, apex of root ; the first layer of cells within v is epidermis ; i\ its thickened 

 outer wall ; within the epidermis, several layers of cortex ; u-fg, belong to the pleronie cylin- 

 der. (Sachs. ) 



Fig. 289. Protoplasm in cells of Maize. A, cells from a young leaf-sheath, showing numerous 

 vacuoles separated by thin plates of protoplasm. B, cells from the first internode of the ger- 

 minating i)lant. Here the protoplasm is broken up into rounded masses. h. vacuole ; k. 

 nucleus. (Sachs.) 



Fig. 290. A, cell of endosperm of Maize. Thin plates of protoplasm separate the polygonal starch- 

 grains, a — </, starch granules from germinating seed, in various stages of disintegration. (Sachs.) 



Fig. 291. Cross-section of fibro-vascular bundle of Maize, p, parenchyma of ground-tissue ; </. 

 outer side, i, inner side of bundle; (j, <j. pitted vessels; s, spiral vessel; r, annular vessel; /. 

 intercellular space filled with air; r,r, soft bast; the outer tissue of the bundle consists of 

 thick- walled prosenchyma. (Sachs. ) 



Fig. 292. Cross-section of stem of ^laize, showing parenchyma, yic, partition-wall of cellulose ; 

 z, intercellular spaces. (Sachs.) 



