. The origin of a land flora, a theory based upon the facts of alternation. Plant morphology. Fig. 37. Apospory. A — Soral-apospory of A thyriumjilixfoemina, var. clarissima. Jones. Part of a pinnule with veins (vb) and a sorus. In the latter, in place of the sporangia,prothalli are formed (prtk) with antheridia (antft) and archegonia (arch). X40. B = apical apospory of Polystichum angulare^ var. fiulcherrimum. Padley. A prothallus at the tip of a pinnule, as a direct continuation of it. £/=marginal glandsj c=the cushion. X20. C=the first initiation of a prothallus as in B, at the apex of a pi
. The origin of a land flora, a theory based upon the facts of alternation. Plant morphology. Fig. 37. Apospory. A — Soral-apospory of A thyriumjilixfoemina, var. clarissima. Jones. Part of a pinnule with veins (vb) and a sorus. In the latter, in place of the sporangia,prothalli are formed (prtk) with antheridia (antft) and archegonia (arch). X40. B = apical apospory of Polystichum angulare^ var. fiulcherrimum. Padley. A prothallus at the tip of a pinnule, as a direct continuation of it. £/=marginal glandsj c=the cushion. X20. C=the first initiation of a prothallus as in B, at the apex of a pinnule. The shading indicates a vein beyond the tip of which the prothallus arises. X 130. £)—b. similar growth, but borne on an elongated cylindrical process: archegonia {arch) are already present. X10. A=soral apospory in Polystichum angulare, var. fiulcherrimum. A prothalloid growth bearing an antheridium (anth) and rhizoids (h) has arisen from the stalk of a sporangium. X 70. f E. 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. London, Macmillan and Co. , Ltd.
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