. Morphology of spermatophytes. [Part I. Gymnosperms]. Gymnosperms; Plant morphology. CYCADALES 7 imler, and the iimcilnge canals passing- on to join the cortical canal system. The xylem elements are of the general Gynmosperm cliarac- ter. They are all tracheitis, the first formed being spiral in type anil tlie later sealariform; while in the tracheids of the secondary xylem the characteristic bordered pits appear, or a mixture of sealariform and reticulate thickenings may be developed, as in Zainin. ]\Incilage ducts are common in all organs, and the pith is also remarkably rich in stored star
. Morphology of spermatophytes. [Part I. Gymnosperms]. Gymnosperms; Plant morphology. CYCADALES 7 imler, and the iimcilnge canals passing- on to join the cortical canal system. The xylem elements are of the general Gynmosperm cliarac- ter. They are all tracheitis, the first formed being spiral in type anil tlie later sealariform; while in the tracheids of the secondary xylem the characteristic bordered pits appear, or a mixture of sealariform and reticulate thickenings may be developed, as in Zainin. ]\Incilage ducts are common in all organs, and the pith is also remarkably rich in stored starch. TJIE LEAF The alternation of rosettes of scale leaves and foliage leaves near the aj^ex of the stem is a conspicuous feature. According to Goeljel, every year or every other year a rosette of foliage leaves is expanded, in the center of which is a terminal bud. FHi. Cross section of u leaf of C'l/cas reoolnta. invested by numerous scale leaves imder whose protection a new rosette of foliage leaves slowly develops (Fig. 1). In the green- house material we have examined there are no such regular peri- ods of unfolding. The alternation is still more striking when sporopliylls are included, scale leaves, foliage leaves, and sporo- pliylls being the order of succession. The scale leaves are brown and dry. The foliage leaves are pinnate and leathery, and generally de\'olop expanded, but in. 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 Coulter, John Merle, 1851-1928; Chamberlain, Charles Joseph, b. 1863. New York, D. Appleton
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Keywords: ., bookauthorcoulterj, bookcentury1900, bookdecade1900, bookyear1901
