Miscellaneous. 155 
pense of the vitellus, within its homogeneous and amorphous envelope 
—the vitelline membrane. 
*©2. Referring to cryptogamic plants, nothing is more striking than 
the identity between the segmentation of the contents of the spores 
for the development of sporules, or the division of the contents of the 
latter for the formation of embryonary cells and the like pheeno- 
menon in animals (see the works of Thuret and Decaisne). More- 
over, one cannot hesitate to compare the spores or the sporules of 
cryptogamic plants with the ovule of animals,—their homogeneous 
envelope with the vitelline membrane, and their granular contents 
with the vitellus. With respect to the differences which, in this 
point of view, exist between the formation of spores and their ger- 
mination among fungi and microscopical alge, they constitute no 
more than mere varieties of the phenomenon of segmentation, and 
such are to be met with in higher organizations, and the gradual 
simplification or degradation may be traced. 
‘3. In phanerogamous plants the embryonary sac appears in the 
form of a transparent cell in the nucleus of the ovule: its contents 
very soon become granular and form a true vitellus. After fecun- 
dation two nuclei make their appearance, around which the granular 
matter of the vitellus collects itself; in the line of separation between 
these two spherical bodies a dissepiment appears, indicating the for- 
mation of the membrane to envelope each of them and to transform 
them into embryonary cells; this effected, each of the latter subdivide 
into two, and soon. Here it is still evident that the embryonary cells 
are formed after the same fashion as in animals, and these facts show 
that the embryonary sac of phanerogamous plants is the only part of 
them comparable with the ovum of animals. We have in it the true 
ovule of plants, in the form ofa cell, soon displaying a homogeneous 
envelope or vitelline membrane, and a granular interior or vitellus. 
As to the primine, secundine, and nucleus or tercine, these are but 
organs composed of cellular tissue, organs of protection or of nutri- 
tion, and accessory only to the essential part—the ovule. 
**B. Analogy between the product of the male organs and that of the 
ovaries of the female among plants and animals, and identity between 
the mode of formation in the male ovule of the grains of pollen or of 
spermatozoa, and that of the embryonary cells in the female ovule. 
“|. All botanists agree in describing, in each half of the young 
anther, the development of large cells, out of which the grains of 
pollen are formed, and which are called the parent-cells of pollen, or 
pollen-utricles. ‘These utricles are made up of granular contents, 
constituting a true vitellus analogous to that of the vegetable ovule, 
and inclosed by a homogeneous wall, or vitellme membrane. In 
the vitellus, at first two, and afterwards four nuclei appear, around 
which the vitelline granules congregate, in such a way as to form 
so many small spheres, each of which soon becomes furnished with 
an inclosing envelope. ‘These cells thus formed, after some modi- 
fication of their walls, constitute grains of pollen. The analogy in 
the formation of the latter to that of the embryonary cells in the 
ovule, or embryonary sac of the plant, cannot fail to be observed, in 
