402 



Vegeta hie Phys iolocjy . 



granules first appear in this as small globules, separate, and uni- 

 formly diffused through the protoplasm ; solution of iodine 

 colours them blue, while the matrix of nitrogenous matter turns 

 yellow. By degrees, in the outer parts of the grain, the grains 

 enlarge, until they come nearly into contact, and, to adjust them 

 closely together, their original rounded form changes to poly- 

 gonal, in which shape they appear densely packed in the ripe 

 seed. On applying iodine to sections of the ripe seed, however, 

 a thin stratum of yellow protoplasm is seen interposed between 

 the adjacent grains. 



Fig. 17. 



A. Cells from the stem of the white 

 lily, containing nuclei (a) adherent 

 to the protoplasm (d) lining the 

 cell-wall, and, more or le,ss con- 

 nected with these, tracts of proto- 

 plasm, in which are forming chloro- 

 jihyll and starch granules (b). Mag- 

 nified 20U diameters. 



B. Fragment of another cell magnified 

 801) diameters, after treatment with 

 iodine : a, nucleus ; c, starch gi'.i- 

 n\iles imbedded in protoplasm ((/), 

 which in other parts exhibits " va- 

 cuoles," or water-bubbles. 



Chlorophyll-granules, pro- 

 ducing starch; a, young 

 chlorophyll-granules ; b, 

 similar granules, wilh 

 water-bubbles caused by 

 endosmose ; e, round chlo- 

 rophyll-granules colieren t 

 in groups ; li, the same in 

 a more advanced stage, 

 containing starch-granules, 

 the chlorophyll forming a 

 mere film over the surface 

 (all the above from the 

 young fruit of Sphcfro- 

 carpus tcrrestris) ; t:,f, g, 

 chlorophyll granules from 

 the prothallium of a Fern ; 

 f and g, older ones, in 

 which starch-grannies are 

 forming. All magiiitied 

 1000 diameters. 



