FREE CELL-FORMATION,. 773 
nucleus cannot be regarded as essential; but the portion of 
protoplasm, which in such cases separates from the general mass, 
must be capable of covering itself witha membrane and forming 
a cell. This, according to Mohl, frequently occurs in the for- 
mation of the spores of the Algw, &c. 
Fra. 1128. Fig. 1129. 
Fig. 1128. Cells from the embryo- 
sac of Chamcedorea Schiedeana 
in theactofformation. «. The 
youngest part, consisting of 
nuclei and protoplasm. 0. 
Newly formed cells. c,d. Cells 
still further developed, with 
nuclei adhering to their sides. 
(After Schleiden. ) Fig. 1129. 
2. The part of fig. 1128, a, more 
highly magnified. 3. A nucleus 
still more highly magnified. 4. 
A nucleus with the cell forming 
upon it. 5. The same more 
highly magnified. 6. The same: 
the nucleus here shows two 
nucleoli. 7. The nucleus of 6, 
after the destruction of the cell 
by pressure. 8. The cells of 
Jig. 1128, d, in a higher degree 
of development, the cell-wal!s 
having already united. (After 
Schleiden.) 
In Flowering Plants free cell-formation has been generally 
believed to occur in the embryo-sac, in which part, after im- 
pregnation, the germinal vesicles, the antipodal cells, and the 
cells of the endosperm thus originate. In Flowerless Plants 
it is the mode by which the spores in the asci of Lichens, Algve, 
and Fungi are developed. 
In the ordinary course of vegetation, free cell-formation can 
