. Morphology of spermatophytes. [Part I. Gymnosperms]. Gymnosperms; Plant morphology. CONIPERALES 79. fertilization, which occurs about the 1st of July, at least twenty- one months after the first organization of the ovule. It should also be remembered that after fertilization the seed is not shed until the following year, fully three years after the first appearance of the ovule. Practically the same history was reported by Strasburger ^* in the case of Larix, and it probably represents a common condition among Conifers, a condition which is hard to detect without the greatest care. The porti
. Morphology of spermatophytes. [Part I. Gymnosperms]. Gymnosperms; Plant morphology. CONIPERALES 79. fertilization, which occurs about the 1st of July, at least twenty- one months after the first organization of the ovule. It should also be remembered that after fertilization the seed is not shed until the following year, fully three years after the first appearance of the ovule. Practically the same history was reported by Strasburger ^* in the case of Larix, and it probably represents a common condition among Conifers, a condition which is hard to detect without the greatest care. The portion of this long history which concerns us at present ends with the dis- tinct organization of the mother cell, and it is this very period which seems to have received the least attention. There is cur- rent the general statement that the arche- sporium is differentiated very early as one or more hypodermal cells. While the probabilities are largely in favor of the truth of this statement, we have discovered no complete series of figures to substan- tiate it except those of Larix given by Strasburger.^* In the same connection he gives certian figures of Taxus which indi- cate the same fact, and also remarks that Thuja, Pinus silvestris, and Pinus Pu- milio are essentially the same as Larix in this regard. It should be remembered, therefore, that the only close series is from Larix, and that the series is the same in other forms is more or less a matter of inference from fragmentary observations (rig. 61). A periclinal wall divides each archesporial cell into an outer primary wall cell and an inner primary sporogenous cell. The wall cells divide repeatedly, and as these divisions are accom- panied by division of the overlying epidermal cells an extensive mass of sterile nucellar tissue is developed between the micro- pyle and the sporogenous cells. Moreover, the divisions are so regular that definite rows of sterile cells extend from the sporog- enous tissue to the tip of the nuc
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