. Text-book of botany, morphological and physiological. Botany. 368 surface of the ground from the time that the spores become ripe till the next autumn, when the root-hairs again produce a new protonema, and upon this new stems arise. Similar outgrowths from the roots occur also, according to Schimper, in the felted protonema of some species of Polyirichum (P. nanum and abides) on the slopes of hollow roads, and on that of Schisloskga osmundacea in dark hollows. The root-hairs may also immediately produce leaf-buds, and behave, in this respect, exactly like the protonema. When the
. Text-book of botany, morphological and physiological. Botany. 368 surface of the ground from the time that the spores become ripe till the next autumn, when the root-hairs again produce a new protonema, and upon this new stems arise. Similar outgrowths from the roots occur also, according to Schimper, in the felted protonema of some species of Polyirichum (P. nanum and abides) on the slopes of hollow roads, and on that of Schisloskga osmundacea in dark hollows. The root-hairs may also immediately produce leaf-buds, and behave, in this respect, exactly like the protonema. When the buds arise on underground ramifications of the root-hairs (Fig. 250, B) they remain in a dormant state, as small microscopic. FIG. 250.—^ young plant of a Barbula (m) with the root-hairs h, to the growing ends of which particles of earth have become attached; at p a superficial root-hair is putting out branches containing chlorophyll, in other words a protonema; at k a tuberous bud (bulbil) is growing from an underground branch of the root-hairs; B this bud more strongly magnified (A x 20 ; B X 300). tuberous bodies (bulbils) filled with reserve food-material, until they chance to reach the surface of the ground, when they undergo further development { Barbula muralis, Grimmia pulvinala, Funaria hygromeiricai Trichostomum rigidum^ Atrichurri). The aerial root-hairs may, however, not only produce a protonema containing chlorophyll, but also leaf-buds without its intervention; and Schimper cites the remarkable fact that in Dicranum undulalum annual male plants are formed in this manner on the tufts of perennial female plants, and fertilise the latter. Even the leaves of many Mosses produce a protonema, their cells simply growing, and the tubes thus formed becoming segmented. This occurs in Oriho-. 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
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1882
