. Morphology of gymnosperms. Gymnosperms; Plant morphology. 338 MORPHOLOGY OF GYMNOSPERMS into the nucellus. Torreya californica is said to difier in that male cells are not formed, but the two male nuclei are invested by the general cytoplasm of the body cell, and with no inequality (99). In Taxus the microspore is shed in the uninucleate stage, the division into generative and tube cells occurring while the spore is resting on the tip of the nuceUus, and the pollen tubes are in the nucellus only about two months before fertilization; otherwise the events are exactly as in Torreya, including
. Morphology of gymnosperms. Gymnosperms; Plant morphology. 338 MORPHOLOGY OF GYMNOSPERMS into the nucellus. Torreya californica is said to difier in that male cells are not formed, but the two male nuclei are invested by the general cytoplasm of the body cell, and with no inequality (99). In Taxus the microspore is shed in the uninucleate stage, the division into generative and tube cells occurring while the spore is resting on the tip of the nuceUus, and the pollen tubes are in the nucellus only about two months before fertilization; otherwise the events are exactly as in Torreya, including the formation of two very unequal male cells (fig. 387). In Cephalotaxus the first division of the microspore (to generative and tube cells) occurs before shedding, as in Torreya. Pollination occurs from January to March (varying with the species and the latitude), but no further division occurs until the following spring, when the gen- erative cell divides, and the body cell and stalk and tube nuclei are found in the pollen tube; in fact, the tube does not penetrate the nucel- lus for nine to twelve months after pollination (124, 130). The two accounts of Cephalotaxus difier as to the character of the male cells, which are said to be unequal in C. Fortunei (124), and in C. drupacea (130) to be represented by two male nuclei, without wall-formation (fig. 388). The inequality of the cells in the former species is not so great as in Torreya and Taxus; and since in- equality is chiefly that of the cytoplasm rather than of the nuclei, the absence of wall-formation in the latter species might result in no appearance of inequality. In both cases the tube reaches the female ga;metophyte quickly (in about ten days in C. drupacea); and in C. Fortunei it reaches the archegonium neck before the chamber is formed, so that the endosperm grows up about the tip of the tube and may bury the archegonia. The features of the male gametophyte of Taxineae, therefore, are the absence of vegetative (
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