. Botany for agricultural students . Botany. TRUE MOSSES (BRYALES) 421 cycle as shown in Figure 376. The Alga-Uke filament called protonema is comparable to the thallus of the Marchantias, and the leafy plants to the gametophores. Although the leafy plants or gametophores of Moss are not all of the gametophyte, they are the conspicuous part of it, the protonemas being microscopic in size. One protonema may produce many buds, and, therefore, many gametophores. In Moss the two generations are more noticeable than in the Liverworts. The gametophytes with their leafy gametophores present more diff
. Botany for agricultural students . Botany. TRUE MOSSES (BRYALES) 421 cycle as shown in Figure 376. The Alga-Uke filament called protonema is comparable to the thallus of the Marchantias, and the leafy plants to the gametophores. Although the leafy plants or gametophores of Moss are not all of the gametophyte, they are the conspicuous part of it, the protonemas being microscopic in size. One protonema may produce many buds, and, therefore, many gametophores. In Moss the two generations are more noticeable than in the Liverworts. The gametophytes with their leafy gametophores present more differentiation than is the rule among Fig. 376. — Diagram of the life cycle of Moss, p, protonemas from which the gametophores (g) have arisen; a and 6, the sex organs with a sperm shown passmg from antheridium to archegonium; c sporophyte which the fertilized egg produces; s, spores which grow new protonemas and thus the life cycle is completed. The sporophyte, consisting of a large sporangium supported on a long stalk, or seta, is usually quite conspicuous. It is more multi- cellular and has carried the sterilization of sporogenous tissue farther than the sporophytes of most Liverworts have. Not only is it larger and more multicellular, but it also shows more differentiation than the sporophytes of Liverworts. The seta is so differentiated as to have a central strand of elongated cells for conduction. The sporangium of the Moss sporophyte develops at its top a special lid-like structure (operculum) for opening, and often special tooth-like structures (peristome) are produced just under the lid and assist in scattering the 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 Martin, John N. (John Nathan), b. 1875. New York : John Wiley & Sons, Inc.
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