ee = 
a 
re 
iS 
2 
The Vegetable Individual, in its relation to Species. 307 
an individual seems to be decided by these facts; that of the 
entire plant, asa superior whole composed of individual cells, 
seems to be settled, and a firm foundation for the doctrine of veg- 
‘etable individuality to be gained. But let us try to obtain a 
clearer view of some of the most important of these facts. The 
view which regards all cell-formation as a process of reproduction 
rests n observations of the formation of free daughter-cells 
(blastidia) in the contents of the mother-cells (matrices ),—the 
so-called free, or endogenous, cell-formation. Schleiden, who dis- 
covered this process, and Karstent the most decided and original 
of his followers, regarded endogenous formation as the universal 
law of cell-formation. By this view the whole doctrine was 
turned in a wrong course, from which it could only be gradually 
recovered by the discovery, or rather the farther investigation, 
of another mode of cell-formation, which Nageli designated as 
“wandstindige,” Unger as “ merismatic,’’ and Mohl as “ cell-for- 
mation by division of the primordial utricle.” But even at this 
day the misconception caused by generalizing the view that new 
cells are formed within old ones, en entirely removed. 
I have alreadyt called attention to the fact that cells are divided 
Which have no cell-wall, which is often the case among the 
lge.§ In several genera in which numerous spores are formed 
ind subsequent divisions there is no formation of new cells éz 
old ones, of daughter-cells in mother-cells, and hence no repro- 
Uction, in the sense of one or more individuals being produced 
_™ an old one. The entire mother-cell is converted into two 
filial cells; the filial cells are nothing but the mother-cell divided. 
And this is essentially the case in every cell-formation by division : 
‘or the wall of the mother-cell (within which the division gener- 
aaier Palmellacese, Desmidiacex, and Diatomex. Cf Braun ; Verjiingung, p. 132, 
cts every mode of cell-for- 
cell originates at its first 
fi 
