312 ON THE GERMINATION OF CHAEA. 



I haye in vain tried to determine by direct observation, the 

 length of time consumed in the different stages of germination 

 described, because the young plants ceased to grow after being placed 

 under the microscope. However, from the relative frequency with 

 which the germinating plants were daily passed in review, it appears 

 tolerably certain that all the normal divisions of the germinating 

 plant, including that of the stem-node, are very rapidly completed, 

 within twenty-four hours at the outside. The elongation of the parts 

 which now follow is a slower process. The divisions in the accessory 

 pro-embryos do not succeed each other so quickly, and therefore the 

 different stages are more easily seen. 



I have nothing to say here respecting deviations from normal 

 structure, because I have not anything new to add, and their relative 

 variety renders them of no importance in the questions considered 

 in this paper. 



Explanation of Tabs. 167, 168.* 



In all the figures representing entire germinating plants the letters sig- 

 nify : — 



b. Basal-cell (with shell), 

 w. First node. 

 r. Root-node. 



s. Stem-node of the pro-embryo. 



i. Tip of the primary or principal pro- embryo, or its position. 

 tt. Tip of the accessory pro-embryos. 

 p.r. Primary root. 

 The exact proportions of the enlargements are not given in all cases, because 

 the instruments used for some of the observations are no longer at my disposi- 

 tion, and their magnifying powers were not calculated at the time. 



Figs. 1 — 4. Chara fcetida. 



Figs. 1 and 2 magnified about 90 diams. Oospores in glycerine, beginning 

 to germinate, after solution of the chalk by muriatic acid. In fig. 1 the separa- 

 tion of w. isjust beginning, in 2, t. and^j).r. fully separated and growing out, the 

 base of the primary root already divided. 



Fig. 3 and 4 magnified about 300 diams. The crown of the basal cell, with 

 »?., prepared free, fig. 8 from above, fig. 4 side profile. The primary halving- wall 

 begins with a division of the shrinking protoplasm. 



Figs. 5 — 10, Chara crinita. 



Fig. 5, magnified less than 100 diams., germinating oospore with advanced 

 pro-embryo and primarj'^ root. 



Fig. 6. An older germinating plant, enlarged about 8 times. At s the first 

 stem with fully encrusted (corticated) lower internodes. 



Fig. 7— 10, magnified 145 diams. Cross sections of the root-node. Fig. 7 

 from a younger primary pro-embryo, figs 8 and 9 from accessory pro-embryos of 

 about the same stage of development as tt. in fig. 6. Fig. 10 from a primary 

 pro-embryo of the age of t. in fig. 6 ; this section passes somewhat obliquely 

 through the middle of the node. The rudiments of roots a a. are below the 

 level of the face of the section, c was turned obliquely upwards, d older roots. 



Figs. 11 — 17. Tohjpclla intrieata. 

 Fig. 11, magnified 145 diams. Commencement of germination, after re- 

 moving the chalk from shell with acetic acid glycerine. The nodal cell appeared 

 undivided in a free preparation. 



• We are indebted to the proprietor of the *' Botanische Zeitung " for per- 

 mission to reproduce this selection from the figures accompanying Prof. De 

 Bary's memoir. — \_Ed. Jo^irn. Bot,'\ 



