894 M. Mtiller on the Development of Chara. 



EXPLANATION OF PLATES V., VI. AND VIL 



Fig. 1. Ripe fruit of Chara vulgaris cut through the axis, and exhibiting the 



internal structure. 

 Fig. 2. The same, showing the exterior. 

 Fig. 3. A portion of the spore-sac more highly magnified. The hrown sporal 



membrane forms its internal border. 

 Fig. 4. The nucleus from Chara vulgaris. 

 Fig. 5. Starch-cells from the same nucleus. Fig, 20. A cell converted into 



cytoblastema, magnified 400 diameters. 

 Fig. 6. The germinating spores of Ch. vulgaris. 

 Fig. 7. The lowermost part of the germ, containing a distinct primordial 



utricle, cytoblasts, their fibres, and the cytoblastema deposited in 



the joints, after treatment with iodine. 

 Fig, 8. The same, exhibiting the formation of intercalary cells, treated with 



iodine. 

 Figs, 9, 10. — 10. New plants of Ch. vulgaris formed by intercalary growth. 



9. The earliest stage of the last figure, after treatment with iodine ; 



magnified 300 diameters. 

 Fig. 11. Terminal bud of the stem of Ch. hispida, 400 diameters. Fig. 14, 



The same seen from below. 

 Fig, 12. A portion of the same bud with perfect branches. The cells of the 



shoots are deposited along with their septa, but have not yet as- 

 sumed their vesicular form. 

 Fig, 13. This has taken place here. 

 Fig. 15. A branch of Ch. hispida transversely divided. 

 Fig. 16. A branch with the cells of the shoots forming. 

 Fig. 17. A branch of Ch. hispida with the commencement of the cortical 



formation. 

 Fig, 18. The central cell of the internode, after treatment with nitric acid 



and iodine, 400 diameters. 

 Fig. 19. A branch of Ch. hispida cut through longitudinally. The inter- 



nodial cells are distinctly seen. 

 Fig. 21. Apex of a branch of Ch. crinita, after treatment with iodine. 

 Fig. 22, Apex of a branch of Ch. hispida cut through longitudinally. 

 Fig, 23. Summit of a branch of Ch. hispida with a divided apex. 

 Fig, 24. A part of the apex of a branch of Ch. crinita, after the addition of 



nitric acid and iodine. The secondary membrane is distinctly seen 



internally. One end of the primordial utricle is separated from 



the transverse V\'all of its cell. 

 Fig. 25. The primordial utricle in the lowest articulations of tlie germ of 



Ch. vulgaris. Treated with nitric acid. 

 Fig. 26. The same from the apex of a branch of Ch. hispida, also treated 



with nitric acid. 

 Fig. 27. Apex of a branch of Ch. crinita with the cells of the fruit and 



anthers. 

 Fig. 28. Early state of the fruit of Ch. crinita, 400 diameters. 

 Fig. 29. The same, with the formation of the five terminal cells, 400 diam. 

 Figs. 30 and 31. The same, perfectly formed, 400 diameters. 

 Fig. 32, The same. New cells have become developed within the nucleus 



from cytoblasts : 400 diameters. 

 Fig. 33. The same. The cells of the spore-sac are arranged spirally around 



the nucleus : 250 diameters. 

 Fig. 34. The perfectly formed fruit of Ch. crinita, 250 diameters. 

 Fig. 35. Its five terminal cells, seen from above, 400 diameters. 

 Fig. 36. The same from the young fruit, 400 diameters. 



