M. Miller on the Development of Chara. 328 
XLII.—On the Development of Chara. By C. Mitier*. 
[Continued from p. 262.] 
§ 5. The perfect Plant. 
Tuer modifications of the development of the stem in Nitella have 
been traced with tolerable completeness. In Chara, however, the 
simple tubes are covered externally with utricular cells which are 
arranged spirally around them. These are not formed until after 
the germinating plant has become much elongated and its rami- 
fications have acquired considerable increase. In a plant which 
has attained this stage of development several peculiarities are 
apparent. Such are the evolution of axillary cells to form axillary 
branches, and the formation of other more or less rounded cells 
in ascending and descending rows at the articulations of the stem ; 
lastly, the formation on the stem itself of new papillary cells 
which are identical with those last mentioned, as in Chara his- 
pida and crinita, where they sometimes again elongate into arti- 
culated tubes, and thus give the plants a very rough appearance. 
The cells themselves do not differ at all in their internal struc- 
ture from those of the spore-sac. How are these organs formed? 
How are the utricular (cortical) cells formed around the central 
utricle? Here the process of development of the entire plant is 
far more complicated than that of the germ. Moreover the his- 
tory of the development of all the organs, of the branches, shoots, 
and even of the stem itself, is intimately connected, and we must 
again commence with the stem. | 
To trace the formation of the stem, we must search for that 
point at which it is developed. This is its apex, the terminal bud ; 
which consists externally of a single large cell forming the im- 
mediate continuation of the stem, and as such, terminating it in 
the form of a cupola (Pl. VI. fig. 11). The bud appears of the 
same form in the centre of the recently formed whorl of branches 
whilst still short. Its membrane is extremely delicate and there- 
fore easily injured. It contains a reddish granular matter (cyto- 
blastema), which too frequently renders it impossible to arrive 
clearly at the structure of the bud. If we succeed, however, in any 
way in removing it—which can only be effected by dissection, for 
iodine and acids render the contents still more obscure—we find. 
the whole of the interior already covered with cells with exceed- 
ingly delicate walls (fig. 14). [In this figure the preparation 
fig. 11 is placed on its vertex, and we are supposed to look in- 
ternally from above towards the vertex.] This cellular structure 
consists of a central cell, around which some other cells are de- 
* Translated from the Botanische Zeitung for June 26, 1845. 
