. Botany for academies and colleges: consisting of plant development and structure from seaweed to clematis. Botany; 1889. 46 ACADEMIC BOTANY. is no ovary, style, nor stigma. The open micropyle (Fig. 47, C, m) secretes a fluid on which the pollen-grain is held when the wind bears it to the ovule. Here it germinates; then it sends out a tube (Fig. 47, B, ps\ which, as we know, is a prolongation of the intine, and which contains the fovilla, or nourishment (19). The extine, as we have al- ready learnt (20), has no special openings provided for the emission of the pollen-tube; it bursts irregular
. Botany for academies and colleges: consisting of plant development and structure from seaweed to clematis. Botany; 1889. 46 ACADEMIC BOTANY. is no ovary, style, nor stigma. The open micropyle (Fig. 47, C, m) secretes a fluid on which the pollen-grain is held when the wind bears it to the ovule. Here it germinates; then it sends out a tube (Fig. 47, B, ps\ which, as we know, is a prolongation of the intine, and which contains the fovilla, or nourishment (19). The extine, as we have al- ready learnt (20), has no special openings provided for the emission of the pollen-tube; it bursts irregularly. We see in the Pine pollen-grain a trace of the prothallus of the Cryptogams (Fig. 47, B, y); here it is a small cell cut off from the true or pollen-cell. We know also (20) that the process of both fertilization and fruit-ripening is very slow. 78. The Joint-Firs, or Sea-Grapes, are low seaside plants with slender, jointed, green-barked branches destitute of foliage, except the minute leaves at the joints. The flowers now have bracts , which sometimes simulate a perianth; but each flower is still nothing more than a naked ovule. Fig. 48.âJoint-Fir, or Sea-Grape (Ephedra diatachya). A, T'Iiiq }ioq fwn malefla. B, female fls,, which grow in pairs. C, a pair of fe- -â -"'* "do^ LWU male fls., showing the 2 naked ovules, each with an erect style- cOatS the inner like process, which is a prolongation of the tegmen. , ' . (tegmen) pro- longed into a slender .process resembling a pistil; but the process is open at the apex, so that the ovule is still naked (Fig. 48, A, B, C). 79. The Welwitschia belongs with the Joint-Firs. It is a curious dwarf tree of Southwestern Africa. The trunk or stock (Pig. 49) rises but a few inches above the ground. It has two long, ribbon-like leaves, evergreen and parallel-veined, like the leaves of Endogens (Monocot- yledons). These leaves are the cotyledons, put forth when the seed germinates, and persistent through the lifetime of the pl
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