254 F. 0. BOWER. 



Figs, i and 2. — (800.) From the stem of Impatiens parviflora. 

 Fig. 1. Cells from the apical meristem. 



Fig. 2. Mature chloroplastids. a, from the cortex ; b, from the epidermis. 

 Figs. 3 — 7. — (SOO.) From the stem of Tradescantia albiflora. 

 Fig. 3. Cells of the apical meristem. 



Figs. 4 — 6. Gradual iucrease of the plastids. (Picric acid — Hoem ; pre- 

 parations.) 



Fig. 7. Mature chloroplastids . 

 Figs. 8 — 11. — (800.) From the epidermis of the flower of Asphodeline 

 lutea. 

 Fig. 8. Young epidermal cell with colourless plastids ; it was situated be- 

 tween the guard cells of two stomata. 



Fig. 9. Plastids after the formation of starch. 

 Fig. 10. Chromoplastids during development. 

 Fig. 11. Mature chi'omoplastids. 

 Figs. 12 — 14. — (800.) From the epidermis of the flower of Senecio 

 Ghisbrechtii. 

 Fig. 12, Young cell. 

 Fig. 13. Older state. 



Fig. 14, Cell of the mature bud with chromoplastids. 

 Fig. 15. — Bryopsis plumosa. (Picric acid — Hoem.) Isolated discoid 



chromatophores dividing, (800.) 

 Fig, 16, — Zygnema sp. (Picric acid — Hsem.) Cell with the two stellate 

 chromatophores in optical longitudinal section. Starchy sheaths of the 

 " chlorophyll vesicles " consisting of numerous very small starch-grains. 

 Pyrenoids contracted. (800.) 

 Fig. 17.— Hyalotheca mucosa. (Picric acid — Hoem.) Isolated cells, or 

 isolated chromatophores, with various stages of division of the " chloro- 

 phyll vesicles." 



