890 M. Miiller on the Development of Chara. 



XLVIII. — On the Development of Chara. By C. MuLler*. 



[Concluded from p. 329.] 

 § 6. Formation of the Fruit. 



The origin of the fruit must be sought for in the very youngest 

 whorls of branches only. It there exists as one of those external 

 cells which surround the central cell, and is either developed sepa- 

 rately or in combination with the cells of the anther. It differs 

 considerably from the latter^ inasmuch as the latter is a cell pro- 

 duced by intercalary growth which is evolved from the articula- 

 tions of the fruit-cell and is developed downwards^ the former 

 being directed upwards. Whilst at this period the other external 

 cells are elongating to form branches^ the cells of the anther and 

 fruit merely become simply rounded, containing in their interior 

 a yellowish white mass with defined globular outline (the cyto- 

 blastema, Plate VII. fig. 27). The development of the anthers 

 always proceeds more rapidly than that of the fruit, when both 

 occur together; for they may be absent in one and the same spe- 

 cies, as Ch. crinita. 



The next step in the further evolution of the fruit-cell con- 

 sists in the subdivision of its cytoblastema into six parts. It is 

 exceedingly difficult to detect this -, I was only able to succeed by 

 gently compressing the cell, whereupon all that I perceived was, 

 that these globular masses had formed. These should be con- 

 sidered as so many cytoblasts, hence we have one central and five 

 external cytoblasts. From these as many cells are formed by the 

 process with which we are acquainted, during which however the 

 cytoblasts are usually perfectly absorbed (fig. 28). These six cells 

 are so arranged, that the apex of each is situated externally. This 

 is the first stage at which anything definite can be perceived in 

 the young fruit, and although another very small cell constantly 

 exists beneath the central cell, I cannot state anything more re- 

 garding its formation. Suffice to say that it exists there, and is 

 seen in figs. 28 — 32. It forms the commencement of that cell, 

 which has been described above (§ 2), in the ripe fruit, and 

 which is shown in figs. I and 2. The statement there made, that 

 it might be of importance to the existence of the spores, is re- 

 markably borne out by its so early and constant presence, which 

 clearly shows that it is an essential organ of the fruit. 



The five terminal cells which are arranged upon the spore-sac 

 in the form of a crown are next formed, and also from cytoblasts, as 

 may be most distinctly perceived in fig. 29. These here also be- 

 come speedily absorbed, and the cells which are formed around 

 them have become so firmly adherent to one another, that they 



* Translated from the Botanische Zeitung for July 3, 1845. 



