The filaments or stalks of the stamens are made up of very delicate colorless cells, and the centre is traversed by a single fibro-vascular bundle, which is continued up through the centre of the anther. To study the latter, thin cross-sections should be made and mounted in water. Each of the four sporangia, or pollen sacs, is surrounded on the outside by a wall, consisting of two layers of cells, becoming thicker in the middle of the section where the single fibro-vascular bundle is seen (Fig. 81, _H_). On opening, the cavities of the adjacent sporangia are thrown together. The inner cells of the wall are marked by thickened bars, much as we saw in the pine (Fig. 82, _A_), and which, like these, are formed shortly before the pollen sacs open. The pollen spores (Fig. 81, _I_) are large, oval cells, having a double wall, the outer one somewhat heavier than the inner one, but sufficiently transparent to allow a clear view of the interior, which is filled with very dense, granular protoplasm in which may be dimly seen two nuclei (_n_, _ni._), showing that here also there is a division of the spore contents, although no wall is present. The spores do not germinate very readily, and are less favorable for this purpose than those of some other monocotyledons. Among the best for this purpose are the spiderwort (_Tradescantia_) and _Scilla_. Owing to the large size and consequent opacity of the ovules, as well as to the difficulty of getting the early stages, the development and finer structure of the ovule will not be discussed here. The full-grown ovule may be readily sectioned, and a general idea of its structure obtained. A little potash may be used to advantage in this study, carefully washing it away when the section is sufficiently cleared. We find now that the ovule is attached to a stalk (funiculus) (Fig. 81, _G_, _f_), the body of the ovule being bent up so as to lie against the stalk. Such an inverted ovule is called technically, "anatropous." The ovule is much enlarged where the stalk bends. The upper part of the ovule is on the whole like that of the pine, but there are two integuments (i, ii) instead of the single one found in the pine.