Development, and Structure of the Vegetable Cell. 287 
I have represented in Plate VII. the structures observed 
by myself, and which correspond in character with these globules 
of Bary. The phenomenon occurred in Cidogonium grande ; 
the entire contents coalesced into a ball-like mass, which was 
protruded through a circular aperture in the thick-walled joint- 
cell, and formed on the outside a spore-like globule (Pl. VII. 
fig. 50). Alongside the opening there was a small disk, the size 
of the aperture, mostly adherent to one side of it, and which, 
without doubt, had originally closed it before being thrust out - 
by the emerging cell-contents (fig. 50d). The extruded, glo- 
bular, spore-like corpuscle consisted of several nested cells, the 
two outer membranes of which frequently contained a single 
layer of small starch-vesicles, whilst the third was filled with 
chlorophyll and starch, and the fourth was occupied by reddish- 
brown vesicles. 
The globular corpuscle was enveloped within a delicate transpa- 
rent cell as in a sac, which was fixed by its lower and somewhat 
elongated extremity to the inner wall of the joint-cell near the 
circular aperture. Solution of iodine and chloride of zine gave 
a beautiful violet-blue tint both to the saccular envelope and to 
the membrane of the globule. Bary did not remark this cellu- 
lose reaction of the enveloping sac; and in fact it is difficult to 
produce the coloration in the older globules which have been 
longer extruded from the mother cell. Yet, even under these 
circumstances, the true membranes of the globule are readily 
coloured blue. Ata later phase of their development the starch- 
corpuscles vanish, and their walls become thickened and reticu- 
late, or slightly porous (fig. 52). 
The globule enclosed within the sac exhibits a mucilaginous 
peduncular body at its base, which is adherent, together with the 
lower end of the envelope, to the inside of the “joint-cell. It 
appeared to me to be an inner envelope, which, however, is not so 
extended at this lower extremity as the outer one. The stem- 
like prolongation is also coloured blue by the same reagents. 
Bary considers the saccular envelope to be a young membrane 
formed, probably at the time of extrusion, around the primordial 
sac, and continuous with the innermost layer of the emptied 
joint-cell. Consequently the outer membrane of the globule, or 
the delicate covering which in all probability serves as a lining to 
the sac and is prolonged into its pedicle, would be the secondary 
cell of the joint-cell. 
For my own part, I have not witnessed the first act of coales- 
cence of the cell-contents, but only the formation of such 
globules after they have begun to extrude from the circular 
aperture, and therefore have no knowledge of the origin of the 
different component membranes. 
