30 Prof. H. Karsten on the Formation, 
cell are often to be seen, soon after the action of the aqueous 
solution of iodine, precipitated upon the membranes, upon the 
other cellular contents, and separated from the wall of the 
primary cell by a colourless hyaline fluid; but by-and-by the 
gummy-looking substance diffuses itself through the whole fluid 
intervening between those membranes. 
The colourless and non-nuclear daughter cells (vesicles) seem 
to contain this substance, which is coloured blue by iodine, in 
the most concentrated form; they are always quite filled with 
it. Both in them and in the gum-like contents of the mother 
cell, coloured blue by iodine, we may distinguish, when chloride 
of calcium has been employed for maceration, delicate vesicles of 
about the size of the large starch-vesicles which occur in the 
chlorophyll-sac. 
This existence of organized forms as the contents of endo- 
genous cells is of great importance for the right understanding 
of the nature of this material, which is in some degree similar 
to cellulose ; for, were these vesicles not present (and they are 
moreover not unfrequently to be distinguished without the pre- 
paration above described, particularly within the colourless 
daughter cells), we should be entitled to assume that the matter 
interposed between the primary and secondary mother cells was 
an adherent layer, swollen up and chemically modified by the 
corroding substances, upon the internal surface of the former or 
on the outer surface of the latter. 
Moreover, if it were impossible to recognize the delicate mem- 
brane of the secondary cells within the limits of the contracted 
chlorophyll-sac &c. after the blue colour fades by the evapora- 
tion of the iodine, the blue-coloured mucilaginous mass between 
the chlorophyll-sac and the primary cell-membrane might be 
regarded as the membrane of the daughter cell modified in the 
same way, with some of the vesicles apparently adherent to the 
chlorophyll-band intermixed with it. 
These circumstances favour the notion that these vesicles en- 
veloped in the gummy substance, for which I propose the name 
celluline, outside the secondary cells, are the remains of the 
contents of the primary joint-cell. 
It is probably to the larger or smaller quantity of these con- 
tents of the primary cell, as well as to this change in the condi- 
tion of aggregation of the membrane of the secondary cell, that 
we must attribute the circumstance that the latter, during the 
action of diosmotic fluids, such as glycerine and chloride of cal- 
cium, often separates with difficulty from the membrane of the 
primary, and appears to be glued to this as if by a tenacious 
mucilage. 
In many stages of development, however, the membrane of 
