M. Muller on the Development of Chara. 261 



observed in Chara, because the cells become opake too soon and 

 rarely permit of their contents being distinguished, as they are 

 rapidly deposited on the walls of their cells. One circumstance 

 however remains inexplicable, which is, that in one cell (fig. 9) 

 there are cytoblasts which appear as if they were divided into 

 two parts ; one in the third upper cell still with its apex in the 

 third, the greater part being in the upper one (had the cytoblast, 

 which was formed in the third cell, really ruptured this to form 

 a new cell ?) ; and lastly, that the cytoblast of the uppermost 

 cell, as also the cell itself, appeared as if contracted exactly at the 

 centre ! 



The membrane of the new cells, which is formed in an an- 

 nular manner by the cytoblasts (this is also Schleiden^s view), 

 is MohPs primordial utricle*. It can hardly be seen more beau- 

 tifully in situ in other parts than in the lowermost joint of the 

 stem of the germinating plant (figs. 7 and 8). It is here a simple 

 induration of that external lamina of the cytoblasts which lies im- 

 mediately on the internal periphery of the stem membrane. The 

 membrane which surrounds the cytoblast is perfectly analogous 

 to that produced by induration. Both are coloured yellowish or 

 brownish by iodine. Hence Mohl is correct, when he saysf, " The 

 substance of which the primordial utricle consists, appears, if not 

 identical with, at least nearly related to the mucous granular sub- 

 stance which usually envelopes the nucleus in the form of an ir- 

 regular mass, and from which the mucous threads which are so 

 frequently met with in the young cells emanate, since these dif- 

 ferent portions react in the same manner with iodine and sulphuric 

 acid." We ought to consider them, as stated above,, to be iden- 

 tical. The same author's opinion also J, that the primordial 

 utricle might be of a nitrogenous nature, considering the above 

 reaction of iodine and sulphuric acid, the latter of which does not 

 cause it to disappear, regarded by French chemists as a proof of 

 its containing nitrogen, appears susceptible of direct proof from 

 the above facts. For if the formation of the cytoblastema from 

 starch and that of the cytoblasts and primordial utricle from the 

 former can be directly observed, the conclusion regarding nitro- 

 gen is not too bold, if we remember the large amount of nitrogen 

 contained in the gluten of starch. And starch is always found 

 naturally combined with this substance ! 



When the primordial utricle is once perfectly formed, it ap- 

 pears as a transparent, completely closed peripheral membrane, 

 which is entirely separated by iodine from the outer cell-mem- 

 brane and envelopes the cell-contents. It adheres to it in the 

 upper cells equally as strongly as we previously found it do in 



* Grundzug, 2te Ausg. . f Bot. Zeit; 1844, p. 244. X L. c. p. 305. 



