. Botany of the living plant. Botany; Plants. 532 BOTANY OF THE LIVING PLANT pollination, matures into the hard woody cone, from which the name Coniferae is derived (see Figs. 414, 416). When ripe it consists of a central axis bearing in a complex spiral numerous woody ovidiferous scales. As the cone ripens the scales turn back, and two seeds may be seen freely exposed on the upper surface of each. When fully ripe each seed separates from the scale, together with a thin film of superficial tissue, which on detachment helps to float it away on. SM Fig. 419. Radial section of Pine stem, at the j
. Botany of the living plant. Botany; Plants. 532 BOTANY OF THE LIVING PLANT pollination, matures into the hard woody cone, from which the name Coniferae is derived (see Figs. 414, 416). When ripe it consists of a central axis bearing in a complex spiral numerous woody ovidiferous scales. As the cone ripens the scales turn back, and two seeds may be seen freely exposed on the upper surface of each. When fully ripe each seed separates from the scale, together with a thin film of superficial tissue, which on detachment helps to float it away on. SM Fig. 419. Radial section of Pine stem, at the junction of wood and bast. Phloem to the left, xylem to the right. s = autumn tracheides. *=bordered pits. c= cambium. r=sieve tubes. itf=sieve pits, tm = tracheidal medullary ray cells. sm=medullary ray cells in the wood containing starch. sm' = the same in the bast. £wi=medullary ray cells with protoplasmic content. (x 240.) (After Strasburger.) the breeze (Fig. 414, B). The seed is protected by a seed-coat, covering a bulky endosperm, with a large embryo enclosed in it, which has many cotyledons, a plumule and radicle. The seed is thus " albu- minous," and in essential points it corresponds to that of Angiosperms. But in the Scots Pine it takes two years to produce, and the details of its production give important features for comparison. Both the types of flower are axillary in their origin. The male flowers are produced in large numbers, replacing the weak foliage spurs (Fig. 420). The female take the place of the stronger branches of unlimited growth, and are produced in smaller numbers (Fig. 416).. 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 Bower, F. O. (Frederick Orpen), 1855-1948; Wardlaw, C. W. (Claude Wilson), 1901-. London, Macmillan and Co. , ltd.
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