. Botany for high schools. Botany. Fig. 372. Sperms of zamia in pollen tube; pg, pollen grain; an, sperms. (After Webber.) Fig. 373. Sperm of zamia, show- ing spiral row of cilia. (After Webber.) Europe, America, and other countries, as an ornamental tree. It is the sole survivor of a group of plants which were very abundant in geological times. The leaves are triangular, radi- ately veined, and resemble in form the pinnules of the maiden hair fern (Adianfum). The large spore cases form a fleshy fruit, about the size of a plum, with a soft exocarp and a stony endocarp, the meat within being th
. Botany for high schools. Botany. Fig. 372. Sperms of zamia in pollen tube; pg, pollen grain; an, sperms. (After Webber.) Fig. 373. Sperm of zamia, show- ing spiral row of cilia. (After Webber.) Europe, America, and other countries, as an ornamental tree. It is the sole survivor of a group of plants which were very abundant in geological times. The leaves are triangular, radi- ately veined, and resemble in form the pinnules of the maiden hair fern (Adianfum). The large spore cases form a fleshy fruit, about the size of a plum, with a soft exocarp and a stony endocarp, the meat within being the female prothallium or endo- sperm. There are motile sperms, and the life history is similar to that of the cycads. 536. Comparative review of the Gymnosperms.'^—The lowest Gym- nosperms are represented by the cycads. They bear certain resemblances to the ferns, which indicate that they have had their origin from some fern-like ancestors which are not now known. These resemblances are as follows: First, the form of the leaves. * For 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 Atkinson, George Francis, 1854-1918. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
