. The origin of a land flora, a theory based upon the facts of alternation. Plant morphology. 20 THE LIFE-HISTORY OF A FERN of Sporophytic budding. It is plain that such growths are only methods of amplification of the morphological individual ; though ultimately quite separate from the parent plant, there is no reorganisation of the protoplasts involved in their initiation. There is, however, an alternative mode of increase in number of individuals, which deals with much larger numbers of potential germs, and involves a much greater complexity of the phases of production than the mere sporoph
. The origin of a land flora, a theory based upon the facts of alternation. Plant morphology. 20 THE LIFE-HISTORY OF A FERN of Sporophytic budding. It is plain that such growths are only methods of amplification of the morphological individual ; though ultimately quite separate from the parent plant, there is no reorganisation of the protoplasts involved in their initiation. There is, however, an alternative mode of increase in number of individuals, which deals with much larger numbers of potential germs, and involves a much greater complexity of the phases of production than the mere sporophytic budding : it is by means of spores. Since this spore-production is a constant feature in the normal life of all Ferns, and. ml^mw WuSaKJmSi 3/ s- . Fig. 4. Vertical section of the sorus of Nephrodilirn Filix-mas. (After Kny.) indeed of Archegoniates at large, while sporophytic budding only occurs in relatively few, there is good reason to believe that this was a more primitive and important form of propagation. It therefore demands more serious attention. An examination of the leaves of the Male Fern will show in many cases, and especially in young plants, merely a smooth, rather pale green under surface : these are then the vegetative leaves, or " trophophylls," as they are sometimes called, and they always appear first in the develop- ment of the individual. But other leaves of older plants, and especially those formed later in the season, bear on their lower surface, and chiefly near their apical part, numerous roundish patches, which are green or brown according to age : these are the sort, and the leaves bearing them. 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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