836 REPRODUCTION OF THE GYMNOSPERMIA. 
gonia have been discovered, nevertheless the ordinary Fern 
plant is developed from the prothallium by a sort of budding. To — 
this peculiarity Farlow applies the term apogamy ; and quite 
recently Druery describes what he calls apospory in Athyrium 
Filix-jemina, var. clarissima, where the sporangia do not follow 
their usual course of development by producing spores, but, 
assuming amore vegetative character, develop more or less well- 
defined prothallia, which ultimately bear archegonia and anthe- 
ridia. In Polystichum angulare, var. pulcherrima, apospory is 
even more marked, as the prothallium seems to develop in a 
vegetative manner from the spore-bearing plant, without even 
being associated locally with the sporangia. Druery’s observations 
have been confirmed by F. O. Bower. 
2. REPRODUCTION OF THE PHANEROGAMIA.—In all the plants 
belonging to this division of the Vegetable Kingdom the male 
apparatus is represented by one (fig. 512) or more (fig. 26) 
stamens, each of which essentially consists of an anther enclosing 
pollen (fig. 27, p) ; and the female, by one (fig. 583) or (fig. 31) 
more carpels, in (jig. 33) or upon (fig. 7380) which one or more 
ovules are formed. When the ovules are contained in an ovary 
(fig. 35), the plants to which they belong are called angiosperm- 
ous; but when they are only placed upon metamorphosed leaves 
or open carpels, i.e. are naked (fig. 730), the plants are said to 
be gymnospermous. In the plants of both these divisions of the 
Vegetable Kingdom the ovules by the action of the pollen are 
developed into perfect seeds whilst connected with their parent, 
the distinguishing character of a seed being the presence of a 
rudimentary plant called the embryo. The modes in which re- 
production takes place, and the after development of the embryo, 
differ in several important particulars in the Gymnospermia and 
Angiospermia ; hence it is necessary to describe them separately. 
A. Reproduction of the Gymnospermia.—We have already 
given a general description of the pollen and ovules of the 
Phanerogamia, but as these structures present certain differences 
in the Gymnospermia, it will be necessary for us to allude to such 
peculiarities before describing the actual process of reproduction. 
The pollen of the Angiospermia generally consists, as we have 
seen (pages 260-263), of a cell containing a matter called the 
fowilla, and having a wall which is usually composed of two coats, 
the outer being termed the extine, which possesses one or more 
pores (jig. 570) or slits (figs. 568 and 569), or both ; and the | 
inner, called the intine, which is destitute of any pores or slits, 
and consequently forms a completely closed membrane. Each — 
pollen-grain of the Angiospermia is thus generally regarded as a 
single cell ; but as it contains two or more nuclei round which 
the protoplasm is grouped, there is some doubt as to whether it 
should be described as consisting of a single cell. In the Gymno- 
spermia, on the contrary, the pollen-grains are certainly not 
simple cells, but they contain other small cells, each with a 
