. Fundamentals of botany. Botany. 596 STRXJCTURE AND LIFE HISTORIES found in the English "coal balls"' has disclosed both the microsporophylls, bearing pollen-sacs, and the megasporo- phylls, bearing, not merely megasporangia, but true seeds. The ovule a. pollen-chamber, like the cycads, except that it projects a bit through the micropyle, and, strange as it may seem, fossil pollen-grains have been discovered, well preserved within this chamber. The seeds, about }i inch long, have been described as resembling little acorns, en-. FiG. 418.âRestoration of a seed of Lyginodendron
. Fundamentals of botany. Botany. 596 STRXJCTURE AND LIFE HISTORIES found in the English "coal balls"' has disclosed both the microsporophylls, bearing pollen-sacs, and the megasporo- phylls, bearing, not merely megasporangia, but true seeds. The ovule a. pollen-chamber, like the cycads, except that it projects a bit through the micropyle, and, strange as it may seem, fossil pollen-grains have been discovered, well preserved within this chamber. The seeds, about }i inch long, have been described as resembling little acorns, en-. FiG. 418.âRestoration of a seed of Lyginodendron oldhamhim {Lagenos- tema Lomaxi), from a modelby H. E. Smedley. (After Scott.) closed like hazelnuts in smaller glandular cupules (Fig. 418). They are similar to those of the cycads, except that they are not known to have organized an embryo with cotyledons and caulicle. Instead, the tissues of the female gametophyte only are so far found, retained within 'â Coal balls are "concretions of the carbonates of lime and magnesia which formed around certain masses of the peaty vegetation as centers and, through inclosing and interpenetrating them, preserved them from the peculiar processes of decay which converted the rest of the vegetation into coal. In them the mineral matter slowly replaced the vegetable matter, molecule by molecule, thus preserving the cellular structure to a remarkable degree. Such balls are especially frequent in the coal of certain parts of England (Lancashire and Yorkshire).". Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Gager, C. Stuart (Charles Stuart), 1872-1943. Philadelphia, P. Blakiston's son & co.
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Keywords: ., bookauthorgag, bookcentury1900, bookdecade1910, booksubjectbotany
